diff mbox series

drm: Fix EDID firmware load on resume

Message ID 20220727074152.43059-1-matthieu.charette@gmail.com (mailing list archive)
State New, archived
Headers show
Series drm: Fix EDID firmware load on resume | expand

Commit Message

Matthieu CHARETTE July 27, 2022, 7:41 a.m. UTC
Loading an EDID using drm.edid_firmware parameter makes resume to fail
after firmware cache is being cleaned. This is because edid_load() use a
temporary device to request the firmware. This cause the EDID firmware
not to be cached from suspend. And, requesting the EDID firmware return
an error during resume.
So the request_firmware() call should use a permanent device for each
connector. Also, we should cache the EDID even if no monitor is
connected, in case it's plugged while suspended.

Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2061
Signed-off-by: Matthieu CHARETTE <matthieu.charette@gmail.com>
---
 drivers/gpu/drm/drm_connector.c |  9 ++++
 drivers/gpu/drm/drm_edid_load.c | 81 ++++++++++++++++++++++++++++-----
 include/drm/drm_connector.h     | 12 +++++
 include/drm/drm_edid.h          |  3 ++
 4 files changed, 94 insertions(+), 11 deletions(-)

Comments

Takashi Iwai July 27, 2022, 8:18 a.m. UTC | #1
On Wed, 27 Jul 2022 09:41:52 +0200,
Matthieu CHARETTE wrote:
> 
> Loading an EDID using drm.edid_firmware parameter makes resume to fail
> after firmware cache is being cleaned. This is because edid_load() use a
> temporary device to request the firmware. This cause the EDID firmware
> not to be cached from suspend. And, requesting the EDID firmware return
> an error during resume.
> So the request_firmware() call should use a permanent device for each
> connector. Also, we should cache the EDID even if no monitor is
> connected, in case it's plugged while suspended.
> 
> Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2061
> Signed-off-by: Matthieu CHARETTE <matthieu.charette@gmail.com>

Can we simply cache the already loaded EDID bytes instead?
Something like below (totally untested).


thanks,

Takashi

-- 8< --
diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index 1c48d162c77e..b9d2803b518b 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -286,6 +286,7 @@ int drm_connector_init(struct drm_device *dev,
 	connector->status = connector_status_unknown;
 	connector->display_info.panel_orientation =
 		DRM_MODE_PANEL_ORIENTATION_UNKNOWN;
+	connector->firmware_edid = NULL;
 
 	drm_connector_get_cmdline_mode(connector);
 
@@ -485,6 +486,7 @@ void drm_connector_cleanup(struct drm_connector *connector)
 	ida_simple_remove(&dev->mode_config.connector_ida,
 			  connector->index);
 
+	kfree(connector->firmware_edid);
 	kfree(connector->display_info.bus_formats);
 	drm_mode_object_unregister(dev, &connector->base);
 	kfree(connector->name);
diff --git a/drivers/gpu/drm/drm_edid_load.c b/drivers/gpu/drm/drm_edid_load.c
index 37d8ba3ddb46..a38fe4e00e4a 100644
--- a/drivers/gpu/drm/drm_edid_load.c
+++ b/drivers/gpu/drm/drm_edid_load.c
@@ -253,6 +253,13 @@ static void *edid_load(struct drm_connector *connector, const char *name,
 			edid = new_edid;
 	}
 
+	connector->firmware_edid = drm_edid_duplicate((struct edid *)edid);
+	if (!connector->firmware_edid) {
+		kfree(edid);
+		edid = ERR_PTR(-ENOMEM);
+		goto out;
+	}
+
 	DRM_INFO("Got %s EDID base block and %d extension%s from "
 	    "\"%s\" for connector \"%s\"\n", (builtin >= 0) ? "built-in" :
 	    "external", valid_extensions, valid_extensions == 1 ? "" : "s",
@@ -269,6 +276,12 @@ struct edid *drm_load_edid_firmware(struct drm_connector *connector)
 	char *edidname, *last, *colon, *fwstr, *edidstr, *fallback = NULL;
 	struct edid *edid;
 
+	/* already loaded? */
+	if (connector->firmware_edid) {
+		edid = drm_edid_duplicate(connector->firmware_edid);
+		return edid ? edid : ERR_PTR(-ENOMEM);
+	}
+
 	if (edid_firmware[0] == '\0')
 		return ERR_PTR(-ENOENT);
 
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index 3ac4bf87f257..b5d0c87327a3 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -1528,6 +1528,8 @@ struct drm_connector {
 	enum drm_connector_force force;
 	/** @override_edid: has the EDID been overwritten through debugfs for testing? */
 	bool override_edid;
+	/** @firmware_edid: the cached firmware EDID bytes */
+	struct edid *firmware_edid;
 	/** @epoch_counter: used to detect any other changes in connector, besides status */
 	u64 epoch_counter;
Matthieu CHARETTE July 27, 2022, 1:53 p.m. UTC | #2
Hi,

Caching the EDID via the firmware API makes the kernel able to reclaim 
the memory in case it's needed. And eventually, the kernel will load it 
again before suspending.
But for 128 bytes, even if we have many monitors it will not make any 
difference.
I don't know if storing a platform device can take more memory than 128 
bytes of data.
I let you decide which option is better. Just tell me if I should cache 
the bytes instead.

Thanks.

Matthieu

On Wed, Jul 27 2022 at 10:18:48 AM +0200, Takashi Iwai <tiwai@suse.de> 
wrote:
> On Wed, 27 Jul 2022 09:41:52 +0200,
> Matthieu CHARETTE wrote:
>> 
>>  Loading an EDID using drm.edid_firmware parameter makes resume to 
>> fail
>>  after firmware cache is being cleaned. This is because edid_load() 
>> use a
>>  temporary device to request the firmware. This cause the EDID 
>> firmware
>>  not to be cached from suspend. And, requesting the EDID firmware 
>> return
>>  an error during resume.
>>  So the request_firmware() call should use a permanent device for 
>> each
>>  connector. Also, we should cache the EDID even if no monitor is
>>  connected, in case it's plugged while suspended.
>> 
>>  Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2061
>>  Signed-off-by: Matthieu CHARETTE <matthieu.charette@gmail.com>
> 
> Can we simply cache the already loaded EDID bytes instead?
> Something like below (totally untested).
> 
> 
> thanks,
> 
> Takashi
> 
> -- 8< --
> diff --git a/drivers/gpu/drm/drm_connector.c 
> b/drivers/gpu/drm/drm_connector.c
> index 1c48d162c77e..b9d2803b518b 100644
> --- a/drivers/gpu/drm/drm_connector.c
> +++ b/drivers/gpu/drm/drm_connector.c
> @@ -286,6 +286,7 @@ int drm_connector_init(struct drm_device *dev,
>  	connector->status = connector_status_unknown;
>  	connector->display_info.panel_orientation =
>  		DRM_MODE_PANEL_ORIENTATION_UNKNOWN;
> +	connector->firmware_edid = NULL;
> 
>  	drm_connector_get_cmdline_mode(connector);
> 
> @@ -485,6 +486,7 @@ void drm_connector_cleanup(struct drm_connector 
> *connector)
>  	ida_simple_remove(&dev->mode_config.connector_ida,
>  			  connector->index);
> 
> +	kfree(connector->firmware_edid);
>  	kfree(connector->display_info.bus_formats);
>  	drm_mode_object_unregister(dev, &connector->base);
>  	kfree(connector->name);
> diff --git a/drivers/gpu/drm/drm_edid_load.c 
> b/drivers/gpu/drm/drm_edid_load.c
> index 37d8ba3ddb46..a38fe4e00e4a 100644
> --- a/drivers/gpu/drm/drm_edid_load.c
> +++ b/drivers/gpu/drm/drm_edid_load.c
> @@ -253,6 +253,13 @@ static void *edid_load(struct drm_connector 
> *connector, const char *name,
>  			edid = new_edid;
>  	}
> 
> +	connector->firmware_edid = drm_edid_duplicate((struct edid *)edid);
> +	if (!connector->firmware_edid) {
> +		kfree(edid);
> +		edid = ERR_PTR(-ENOMEM);
> +		goto out;
> +	}
> +
>  	DRM_INFO("Got %s EDID base block and %d extension%s from "
>  	    "\"%s\" for connector \"%s\"\n", (builtin >= 0) ? "built-in" :
>  	    "external", valid_extensions, valid_extensions == 1 ? "" : "s",
> @@ -269,6 +276,12 @@ struct edid *drm_load_edid_firmware(struct 
> drm_connector *connector)
>  	char *edidname, *last, *colon, *fwstr, *edidstr, *fallback = NULL;
>  	struct edid *edid;
> 
> +	/* already loaded? */
> +	if (connector->firmware_edid) {
> +		edid = drm_edid_duplicate(connector->firmware_edid);
> +		return edid ? edid : ERR_PTR(-ENOMEM);
> +	}
> +
>  	if (edid_firmware[0] == '\0')
>  		return ERR_PTR(-ENOENT);
> 
> diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
> index 3ac4bf87f257..b5d0c87327a3 100644
> --- a/include/drm/drm_connector.h
> +++ b/include/drm/drm_connector.h
> @@ -1528,6 +1528,8 @@ struct drm_connector {
>  	enum drm_connector_force force;
>  	/** @override_edid: has the EDID been overwritten through debugfs 
> for testing? */
>  	bool override_edid;
> +	/** @firmware_edid: the cached firmware EDID bytes */
> +	struct edid *firmware_edid;
>  	/** @epoch_counter: used to detect any other changes in connector, 
> besides status */
>  	u64 epoch_counter;
>
Jani Nikula Aug. 2, 2022, 2:29 p.m. UTC | #3
On Wed, 27 Jul 2022, Matthieu CHARETTE <matthieu.charette@gmail.com> wrote:
> Loading an EDID using drm.edid_firmware parameter makes resume to fail
> after firmware cache is being cleaned. This is because edid_load() use a
> temporary device to request the firmware. This cause the EDID firmware
> not to be cached from suspend. And, requesting the EDID firmware return
> an error during resume.
> So the request_firmware() call should use a permanent device for each
> connector. Also, we should cache the EDID even if no monitor is
> connected, in case it's plugged while suspended.

AFAICT this breaks changing drm.edid_firmware runtime.

BR,
Jani.

>
> Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2061
> Signed-off-by: Matthieu CHARETTE <matthieu.charette@gmail.com>
> ---
>  drivers/gpu/drm/drm_connector.c |  9 ++++
>  drivers/gpu/drm/drm_edid_load.c | 81 ++++++++++++++++++++++++++++-----
>  include/drm/drm_connector.h     | 12 +++++
>  include/drm/drm_edid.h          |  3 ++
>  4 files changed, 94 insertions(+), 11 deletions(-)
>
> diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
> index 1c48d162c77e..e8819ebf1c4b 100644
> --- a/drivers/gpu/drm/drm_connector.c
> +++ b/drivers/gpu/drm/drm_connector.c
> @@ -31,6 +31,7 @@
>  #include <drm/drm_privacy_screen_consumer.h>
>  #include <drm/drm_sysfs.h>
>  
> +#include <linux/platform_device.h>
>  #include <linux/uaccess.h>
>  
>  #include "drm_crtc_internal.h"
> @@ -289,6 +290,9 @@ int drm_connector_init(struct drm_device *dev,
>  
>  	drm_connector_get_cmdline_mode(connector);
>  
> +	connector->edid_load_pdev = NULL;
> +	drm_cache_edid_firmware(connector);
> +
>  	/* We should add connectors at the end to avoid upsetting the connector
>  	 * index too much.
>  	 */
> @@ -473,6 +477,11 @@ void drm_connector_cleanup(struct drm_connector *connector)
>  		connector->tile_group = NULL;
>  	}
>  
> +	if (connector->edid_load_pdev) {
> +		platform_device_unregister(connector->edid_load_pdev);
> +		connector->edid_load_pdev = NULL;
> +	}
> +
>  	list_for_each_entry_safe(mode, t, &connector->probed_modes, head)
>  		drm_mode_remove(connector, mode);
>  
> diff --git a/drivers/gpu/drm/drm_edid_load.c b/drivers/gpu/drm/drm_edid_load.c
> index 37d8ba3ddb46..5a82be9917ec 100644
> --- a/drivers/gpu/drm/drm_edid_load.c
> +++ b/drivers/gpu/drm/drm_edid_load.c
> @@ -167,6 +167,19 @@ static int edid_size(const u8 *edid, int data_size)
>  	return (edid[0x7e] + 1) * EDID_LENGTH;
>  }
>  
> +static struct platform_device *edid_pdev(const char *connector_name)
> +{
> +	struct platform_device *pdev = platform_device_register_simple(connector_name, -1, NULL, 0);
> +
> +	if (IS_ERR(pdev)) {
> +		DRM_ERROR("Failed to register EDID firmware platform device "
> +			"for connector \"%s\"\n", connector_name);
> +		return ERR_CAST(pdev);
> +	}
> +
> +	return pdev;
> +}
> +
>  static void *edid_load(struct drm_connector *connector, const char *name,
>  			const char *connector_name)
>  {
> @@ -182,18 +195,17 @@ static void *edid_load(struct drm_connector *connector, const char *name,
>  		fwdata = generic_edid[builtin];
>  		fwsize = sizeof(generic_edid[builtin]);
>  	} else {
> -		struct platform_device *pdev;
> +		struct platform_device *pdev = connector->edid_load_pdev;
>  		int err;
>  
> -		pdev = platform_device_register_simple(connector_name, -1, NULL, 0);
> -		if (IS_ERR(pdev)) {
> -			DRM_ERROR("Failed to register EDID firmware platform device "
> -				  "for connector \"%s\"\n", connector_name);
> -			return ERR_CAST(pdev);
> +		if (WARN_ON(!pdev)) {
> +			pdev = edid_pdev(connector_name);
> +			if (IS_ERR(pdev))
> +				return ERR_CAST(pdev);
> +			connector->edid_load_pdev = pdev;
>  		}
>  
>  		err = request_firmware(&fw, name, &pdev->dev);
> -		platform_device_unregister(pdev);
>  		if (err) {
>  			DRM_ERROR("Requesting EDID firmware \"%s\" failed (err=%d)\n",
>  				  name, err);
> @@ -263,11 +275,9 @@ static void *edid_load(struct drm_connector *connector, const char *name,
>  	return edid;
>  }
>  
> -struct edid *drm_load_edid_firmware(struct drm_connector *connector)
> +static char *edid_name(const char *connector_name)
>  {
> -	const char *connector_name = connector->name;
>  	char *edidname, *last, *colon, *fwstr, *edidstr, *fallback = NULL;
> -	struct edid *edid;
>  
>  	if (edid_firmware[0] == '\0')
>  		return ERR_PTR(-ENOENT);
> @@ -310,8 +320,57 @@ struct edid *drm_load_edid_firmware(struct drm_connector *connector)
>  	if (*last == '\n')
>  		*last = '\0';
>  
> -	edid = edid_load(connector, edidname, connector_name);
> +	edidname = kstrdup(edidname, GFP_KERNEL);
> +	if (!edidname) {
> +		kfree(fwstr);
> +		return ERR_PTR(-ENOMEM);
> +	}
> +
>  	kfree(fwstr);
> +	return edidname;
> +}
> +
> +void drm_cache_edid_firmware(struct drm_connector *connector)
> +{
> +	const char *connector_name = connector->name;
> +	const char *edidname = edid_name(connector_name);
> +	struct platform_device *pdev;
> +	int err;
> +
> +	if (IS_ERR(edidname))
> +		return;
> +
> +	if (match_string(generic_edid_name, GENERIC_EDIDS, edidname) >= 0) {
> +		kfree(edidname);
> +		return;
> +	}
> +
> +	pdev = edid_pdev(connector_name);
> +	if (IS_ERR(pdev)) {
> +		kfree(edidname);
> +		return;
> +	}
> +	connector->edid_load_pdev = pdev;
> +
> +	err = firmware_request_cache(&pdev->dev, edidname);
> +	if (err)
> +		DRM_ERROR("Requesting EDID firmware cache \"%s\" failed (err=%d)\n",
> +			edidname, err);
> +
> +	kfree(edidname);
> +}
> +
> +struct edid *drm_load_edid_firmware(struct drm_connector *connector)
> +{
> +	const char *connector_name = connector->name;
> +	const char *edidname = edid_name(connector_name);
> +	struct edid *edid;
> +
> +	if (IS_ERR(edidname))
> +		return ERR_CAST(edidname);
> +
> +	edid = edid_load(connector, edidname, connector_name);
> +	kfree(edidname);
>  
>  	return edid;
>  }
> diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
> index 3ac4bf87f257..47c84741517e 100644
> --- a/include/drm/drm_connector.h
> +++ b/include/drm/drm_connector.h
> @@ -1573,6 +1573,18 @@ struct drm_connector {
>  	 */
>  	struct i2c_adapter *ddc;
>  
> +	/**
> +	 * @edid_load_pdev: Platform device for loading EDID via firmware.
> +	 *
> +	 * The platform device is registered in drm_connector_init() in case a
> +	 * custom EDID firmware is used with `edid_firmware` parameter. Otherwise,
> +	 * it is set to NULL.
> +	 *
> +	 * Platform device is unregistered in drm_connector_cleanup() if it
> +	 * is not NULL.
> +	 */
> +	struct platform_device *edid_load_pdev;
> +
>  	/**
>  	 * @null_edid_counter: track sinks that give us all zeros for the EDID.
>  	 * Needed to workaround some HW bugs where we get all 0s
> diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
> index b2756753370b..e907c928a35d 100644
> --- a/include/drm/drm_edid.h
> +++ b/include/drm/drm_edid.h
> @@ -378,10 +378,13 @@ int drm_av_sync_delay(struct drm_connector *connector,
>  		      const struct drm_display_mode *mode);
>  
>  #ifdef CONFIG_DRM_LOAD_EDID_FIRMWARE
> +void drm_cache_edid_firmware(struct drm_connector *connector);
>  struct edid *drm_load_edid_firmware(struct drm_connector *connector);
>  int __drm_set_edid_firmware_path(const char *path);
>  int __drm_get_edid_firmware_path(char *buf, size_t bufsize);
>  #else
> +inline void
> +drm_cache_edid_firmware(struct drm_connector *connector);
>  static inline struct edid *
>  drm_load_edid_firmware(struct drm_connector *connector)
>  {
Matthieu CHARETTE Aug. 8, 2022, 3:15 p.m. UTC | #4
Sorry, What do you mean?

Matthieu

On Tue, Aug 2 2022 at 05:29:12 PM +0300, Jani Nikula 
<jani.nikula@linux.intel.com> wrote:
> On Wed, 27 Jul 2022, Matthieu CHARETTE <matthieu.charette@gmail.com 
> <mailto:matthieu.charette@gmail.com>> wrote:
>>  Loading an EDID using drm.edid_firmware parameter makes resume to 
>> fail
>>  after firmware cache is being cleaned. This is because edid_load() 
>> use a
>>  temporary device to request the firmware. This cause the EDID 
>> firmware
>>  not to be cached from suspend. And, requesting the EDID firmware 
>> return
>>  an error during resume.
>>  So the request_firmware() call should use a permanent device for 
>> each
>>  connector. Also, we should cache the EDID even if no monitor is
>>  connected, in case it's plugged while suspended.
> 
> AFAICT this breaks changing drm.edid_firmware runtime.
> 
> BR,
> Jani.
> 
>> 
>>  Link: <https://gitlab.freedesktop.org/drm/amd/-/issues/2061>
>>  Signed-off-by: Matthieu CHARETTE <matthieu.charette@gmail.com 
>> <mailto:matthieu.charette@gmail.com>>
>>  ---
>>   drivers/gpu/drm/drm_connector.c |  9 ++++
>>   drivers/gpu/drm/drm_edid_load.c | 81 
>> ++++++++++++++++++++++++++++-----
>>   include/drm/drm_connector.h     | 12 +++++
>>   include/drm/drm_edid.h          |  3 ++
>>   4 files changed, 94 insertions(+), 11 deletions(-)
>> 
>>  diff --git a/drivers/gpu/drm/drm_connector.c 
>> b/drivers/gpu/drm/drm_connector.c
>>  index 1c48d162c77e..e8819ebf1c4b 100644
>>  --- a/drivers/gpu/drm/drm_connector.c
>>  +++ b/drivers/gpu/drm/drm_connector.c
>>  @@ -31,6 +31,7 @@
>>   #include <drm/drm_privacy_screen_consumer.h>
>>   #include <drm/drm_sysfs.h>
>> 
>>  +#include <linux/platform_device.h>
>>   #include <linux/uaccess.h>
>> 
>>   #include "drm_crtc_internal.h"
>>  @@ -289,6 +290,9 @@ int drm_connector_init(struct drm_device *dev,
>> 
>>   	drm_connector_get_cmdline_mode(connector);
>> 
>>  +	connector->edid_load_pdev = NULL;
>>  +	drm_cache_edid_firmware(connector);
>>  +
>>   	/* We should add connectors at the end to avoid upsetting the 
>> connector
>>   	 * index too much.
>>   	 */
>>  @@ -473,6 +477,11 @@ void drm_connector_cleanup(struct 
>> drm_connector *connector)
>>   		connector->tile_group = NULL;
>>   	}
>> 
>>  +	if (connector->edid_load_pdev) {
>>  +		platform_device_unregister(connector->edid_load_pdev);
>>  +		connector->edid_load_pdev = NULL;
>>  +	}
>>  +
>>   	list_for_each_entry_safe(mode, t, &connector->probed_modes, head)
>>   		drm_mode_remove(connector, mode);
>> 
>>  diff --git a/drivers/gpu/drm/drm_edid_load.c 
>> b/drivers/gpu/drm/drm_edid_load.c
>>  index 37d8ba3ddb46..5a82be9917ec 100644
>>  --- a/drivers/gpu/drm/drm_edid_load.c
>>  +++ b/drivers/gpu/drm/drm_edid_load.c
>>  @@ -167,6 +167,19 @@ static int edid_size(const u8 *edid, int 
>> data_size)
>>   	return (edid[0x7e] + 1) * EDID_LENGTH;
>>   }
>> 
>>  +static struct platform_device *edid_pdev(const char 
>> *connector_name)
>>  +{
>>  +	struct platform_device *pdev = 
>> platform_device_register_simple(connector_name, -1, NULL, 0);
>>  +
>>  +	if (IS_ERR(pdev)) {
>>  +		DRM_ERROR("Failed to register EDID firmware platform device "
>>  +			"for connector \"%s\"\n", connector_name);
>>  +		return ERR_CAST(pdev);
>>  +	}
>>  +
>>  +	return pdev;
>>  +}
>>  +
>>   static void *edid_load(struct drm_connector *connector, const char 
>> *name,
>>   			const char *connector_name)
>>   {
>>  @@ -182,18 +195,17 @@ static void *edid_load(struct drm_connector 
>> *connector, const char *name,
>>   		fwdata = generic_edid[builtin];
>>   		fwsize = sizeof(generic_edid[builtin]);
>>   	} else {
>>  -		struct platform_device *pdev;
>>  +		struct platform_device *pdev = connector->edid_load_pdev;
>>   		int err;
>> 
>>  -		pdev = platform_device_register_simple(connector_name, -1, NULL, 
>> 0);
>>  -		if (IS_ERR(pdev)) {
>>  -			DRM_ERROR("Failed to register EDID firmware platform device "
>>  -				  "for connector \"%s\"\n", connector_name);
>>  -			return ERR_CAST(pdev);
>>  +		if (WARN_ON(!pdev)) {
>>  +			pdev = edid_pdev(connector_name);
>>  +			if (IS_ERR(pdev))
>>  +				return ERR_CAST(pdev);
>>  +			connector->edid_load_pdev = pdev;
>>   		}
>> 
>>   		err = request_firmware(&fw, name, &pdev->dev);
>>  -		platform_device_unregister(pdev);
>>   		if (err) {
>>   			DRM_ERROR("Requesting EDID firmware \"%s\" failed (err=%d)\n",
>>   				  name, err);
>>  @@ -263,11 +275,9 @@ static void *edid_load(struct drm_connector 
>> *connector, const char *name,
>>   	return edid;
>>   }
>> 
>>  -struct edid *drm_load_edid_firmware(struct drm_connector 
>> *connector)
>>  +static char *edid_name(const char *connector_name)
>>   {
>>  -	const char *connector_name = connector->name;
>>   	char *edidname, *last, *colon, *fwstr, *edidstr, *fallback = NULL;
>>  -	struct edid *edid;
>> 
>>   	if (edid_firmware[0] == '\0')
>>   		return ERR_PTR(-ENOENT);
>>  @@ -310,8 +320,57 @@ struct edid *drm_load_edid_firmware(struct 
>> drm_connector *connector)
>>   	if (*last == '\n')
>>   		*last = '\0';
>> 
>>  -	edid = edid_load(connector, edidname, connector_name);
>>  +	edidname = kstrdup(edidname, GFP_KERNEL);
>>  +	if (!edidname) {
>>  +		kfree(fwstr);
>>  +		return ERR_PTR(-ENOMEM);
>>  +	}
>>  +
>>   	kfree(fwstr);
>>  +	return edidname;
>>  +}
>>  +
>>  +void drm_cache_edid_firmware(struct drm_connector *connector)
>>  +{
>>  +	const char *connector_name = connector->name;
>>  +	const char *edidname = edid_name(connector_name);
>>  +	struct platform_device *pdev;
>>  +	int err;
>>  +
>>  +	if (IS_ERR(edidname))
>>  +		return;
>>  +
>>  +	if (match_string(generic_edid_name, GENERIC_EDIDS, edidname) >= 
>> 0) {
>>  +		kfree(edidname);
>>  +		return;
>>  +	}
>>  +
>>  +	pdev = edid_pdev(connector_name);
>>  +	if (IS_ERR(pdev)) {
>>  +		kfree(edidname);
>>  +		return;
>>  +	}
>>  +	connector->edid_load_pdev = pdev;
>>  +
>>  +	err = firmware_request_cache(&pdev->dev, edidname);
>>  +	if (err)
>>  +		DRM_ERROR("Requesting EDID firmware cache \"%s\" failed 
>> (err=%d)\n",
>>  +			edidname, err);
>>  +
>>  +	kfree(edidname);
>>  +}
>>  +
>>  +struct edid *drm_load_edid_firmware(struct drm_connector 
>> *connector)
>>  +{
>>  +	const char *connector_name = connector->name;
>>  +	const char *edidname = edid_name(connector_name);
>>  +	struct edid *edid;
>>  +
>>  +	if (IS_ERR(edidname))
>>  +		return ERR_CAST(edidname);
>>  +
>>  +	edid = edid_load(connector, edidname, connector_name);
>>  +	kfree(edidname);
>> 
>>   	return edid;
>>   }
>>  diff --git a/include/drm/drm_connector.h 
>> b/include/drm/drm_connector.h
>>  index 3ac4bf87f257..47c84741517e 100644
>>  --- a/include/drm/drm_connector.h
>>  +++ b/include/drm/drm_connector.h
>>  @@ -1573,6 +1573,18 @@ struct drm_connector {
>>   	 */
>>   	struct i2c_adapter *ddc;
>> 
>>  +	/**
>>  +	 * @edid_load_pdev: Platform device for loading EDID via firmware.
>>  +	 *
>>  +	 * The platform device is registered in drm_connector_init() in 
>> case a
>>  +	 * custom EDID firmware is used with `edid_firmware` parameter. 
>> Otherwise,
>>  +	 * it is set to NULL.
>>  +	 *
>>  +	 * Platform device is unregistered in drm_connector_cleanup() if 
>> it
>>  +	 * is not NULL.
>>  +	 */
>>  +	struct platform_device *edid_load_pdev;
>>  +
>>   	/**
>>   	 * @null_edid_counter: track sinks that give us all zeros for the 
>> EDID.
>>   	 * Needed to workaround some HW bugs where we get all 0s
>>  diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
>>  index b2756753370b..e907c928a35d 100644
>>  --- a/include/drm/drm_edid.h
>>  +++ b/include/drm/drm_edid.h
>>  @@ -378,10 +378,13 @@ int drm_av_sync_delay(struct drm_connector 
>> *connector,
>>   		      const struct drm_display_mode *mode);
>> 
>>   #ifdef CONFIG_DRM_LOAD_EDID_FIRMWARE
>>  +void drm_cache_edid_firmware(struct drm_connector *connector);
>>   struct edid *drm_load_edid_firmware(struct drm_connector 
>> *connector);
>>   int __drm_set_edid_firmware_path(const char *path);
>>   int __drm_get_edid_firmware_path(char *buf, size_t bufsize);
>>   #else
>>  +inline void
>>  +drm_cache_edid_firmware(struct drm_connector *connector);
>>   static inline struct edid *
>>   drm_load_edid_firmware(struct drm_connector *connector)
>>   {
> 
> --
> Jani Nikula, Intel Open Source Graphics Center
Matthieu CHARETTE Aug. 8, 2022, 3:17 p.m. UTC | #5
Sorry, What do you mean?

Matthieu

On Tue, Aug 2 2022 at 05:29:12 PM +0300, Jani Nikula 
<jani.nikula@linux.intel.com> wrote:
> On Wed, 27 Jul 2022, Matthieu CHARETTE <matthieu.charette@gmail.com> 
> wrote:
>>  Loading an EDID using drm.edid_firmware parameter makes resume to 
>> fail
>>  after firmware cache is being cleaned. This is because edid_load() 
>> use a
>>  temporary device to request the firmware. This cause the EDID 
>> firmware
>>  not to be cached from suspend. And, requesting the EDID firmware 
>> return
>>  an error during resume.
>>  So the request_firmware() call should use a permanent device for 
>> each
>>  connector. Also, we should cache the EDID even if no monitor is
>>  connected, in case it's plugged while suspended.
> 
> AFAICT this breaks changing drm.edid_firmware runtime.
> 
> BR,
> Jani.
> 
>> 
>>  Link: https://gitlab.freedesktop.org/drm/amd/-/issues/2061
>>  Signed-off-by: Matthieu CHARETTE <matthieu.charette@gmail.com>
>>  ---
>>   drivers/gpu/drm/drm_connector.c |  9 ++++
>>   drivers/gpu/drm/drm_edid_load.c | 81 
>> ++++++++++++++++++++++++++++-----
>>   include/drm/drm_connector.h     | 12 +++++
>>   include/drm/drm_edid.h          |  3 ++
>>   4 files changed, 94 insertions(+), 11 deletions(-)
>> 
>>  diff --git a/drivers/gpu/drm/drm_connector.c 
>> b/drivers/gpu/drm/drm_connector.c
>>  index 1c48d162c77e..e8819ebf1c4b 100644
>>  --- a/drivers/gpu/drm/drm_connector.c
>>  +++ b/drivers/gpu/drm/drm_connector.c
>>  @@ -31,6 +31,7 @@
>>   #include <drm/drm_privacy_screen_consumer.h>
>>   #include <drm/drm_sysfs.h>
>> 
>>  +#include <linux/platform_device.h>
>>   #include <linux/uaccess.h>
>> 
>>   #include "drm_crtc_internal.h"
>>  @@ -289,6 +290,9 @@ int drm_connector_init(struct drm_device *dev,
>> 
>>   	drm_connector_get_cmdline_mode(connector);
>> 
>>  +	connector->edid_load_pdev = NULL;
>>  +	drm_cache_edid_firmware(connector);
>>  +
>>   	/* We should add connectors at the end to avoid upsetting the 
>> connector
>>   	 * index too much.
>>   	 */
>>  @@ -473,6 +477,11 @@ void drm_connector_cleanup(struct 
>> drm_connector *connector)
>>   		connector->tile_group = NULL;
>>   	}
>> 
>>  +	if (connector->edid_load_pdev) {
>>  +		platform_device_unregister(connector->edid_load_pdev);
>>  +		connector->edid_load_pdev = NULL;
>>  +	}
>>  +
>>   	list_for_each_entry_safe(mode, t, &connector->probed_modes, head)
>>   		drm_mode_remove(connector, mode);
>> 
>>  diff --git a/drivers/gpu/drm/drm_edid_load.c 
>> b/drivers/gpu/drm/drm_edid_load.c
>>  index 37d8ba3ddb46..5a82be9917ec 100644
>>  --- a/drivers/gpu/drm/drm_edid_load.c
>>  +++ b/drivers/gpu/drm/drm_edid_load.c
>>  @@ -167,6 +167,19 @@ static int edid_size(const u8 *edid, int 
>> data_size)
>>   	return (edid[0x7e] + 1) * EDID_LENGTH;
>>   }
>> 
>>  +static struct platform_device *edid_pdev(const char 
>> *connector_name)
>>  +{
>>  +	struct platform_device *pdev = 
>> platform_device_register_simple(connector_name, -1, NULL, 0);
>>  +
>>  +	if (IS_ERR(pdev)) {
>>  +		DRM_ERROR("Failed to register EDID firmware platform device "
>>  +			"for connector \"%s\"\n", connector_name);
>>  +		return ERR_CAST(pdev);
>>  +	}
>>  +
>>  +	return pdev;
>>  +}
>>  +
>>   static void *edid_load(struct drm_connector *connector, const char 
>> *name,
>>   			const char *connector_name)
>>   {
>>  @@ -182,18 +195,17 @@ static void *edid_load(struct drm_connector 
>> *connector, const char *name,
>>   		fwdata = generic_edid[builtin];
>>   		fwsize = sizeof(generic_edid[builtin]);
>>   	} else {
>>  -		struct platform_device *pdev;
>>  +		struct platform_device *pdev = connector->edid_load_pdev;
>>   		int err;
>> 
>>  -		pdev = platform_device_register_simple(connector_name, -1, NULL, 
>> 0);
>>  -		if (IS_ERR(pdev)) {
>>  -			DRM_ERROR("Failed to register EDID firmware platform device "
>>  -				  "for connector \"%s\"\n", connector_name);
>>  -			return ERR_CAST(pdev);
>>  +		if (WARN_ON(!pdev)) {
>>  +			pdev = edid_pdev(connector_name);
>>  +			if (IS_ERR(pdev))
>>  +				return ERR_CAST(pdev);
>>  +			connector->edid_load_pdev = pdev;
>>   		}
>> 
>>   		err = request_firmware(&fw, name, &pdev->dev);
>>  -		platform_device_unregister(pdev);
>>   		if (err) {
>>   			DRM_ERROR("Requesting EDID firmware \"%s\" failed (err=%d)\n",
>>   				  name, err);
>>  @@ -263,11 +275,9 @@ static void *edid_load(struct drm_connector 
>> *connector, const char *name,
>>   	return edid;
>>   }
>> 
>>  -struct edid *drm_load_edid_firmware(struct drm_connector 
>> *connector)
>>  +static char *edid_name(const char *connector_name)
>>   {
>>  -	const char *connector_name = connector->name;
>>   	char *edidname, *last, *colon, *fwstr, *edidstr, *fallback = NULL;
>>  -	struct edid *edid;
>> 
>>   	if (edid_firmware[0] == '\0')
>>   		return ERR_PTR(-ENOENT);
>>  @@ -310,8 +320,57 @@ struct edid *drm_load_edid_firmware(struct 
>> drm_connector *connector)
>>   	if (*last == '\n')
>>   		*last = '\0';
>> 
>>  -	edid = edid_load(connector, edidname, connector_name);
>>  +	edidname = kstrdup(edidname, GFP_KERNEL);
>>  +	if (!edidname) {
>>  +		kfree(fwstr);
>>  +		return ERR_PTR(-ENOMEM);
>>  +	}
>>  +
>>   	kfree(fwstr);
>>  +	return edidname;
>>  +}
>>  +
>>  +void drm_cache_edid_firmware(struct drm_connector *connector)
>>  +{
>>  +	const char *connector_name = connector->name;
>>  +	const char *edidname = edid_name(connector_name);
>>  +	struct platform_device *pdev;
>>  +	int err;
>>  +
>>  +	if (IS_ERR(edidname))
>>  +		return;
>>  +
>>  +	if (match_string(generic_edid_name, GENERIC_EDIDS, edidname) >= 
>> 0) {
>>  +		kfree(edidname);
>>  +		return;
>>  +	}
>>  +
>>  +	pdev = edid_pdev(connector_name);
>>  +	if (IS_ERR(pdev)) {
>>  +		kfree(edidname);
>>  +		return;
>>  +	}
>>  +	connector->edid_load_pdev = pdev;
>>  +
>>  +	err = firmware_request_cache(&pdev->dev, edidname);
>>  +	if (err)
>>  +		DRM_ERROR("Requesting EDID firmware cache \"%s\" failed 
>> (err=%d)\n",
>>  +			edidname, err);
>>  +
>>  +	kfree(edidname);
>>  +}
>>  +
>>  +struct edid *drm_load_edid_firmware(struct drm_connector 
>> *connector)
>>  +{
>>  +	const char *connector_name = connector->name;
>>  +	const char *edidname = edid_name(connector_name);
>>  +	struct edid *edid;
>>  +
>>  +	if (IS_ERR(edidname))
>>  +		return ERR_CAST(edidname);
>>  +
>>  +	edid = edid_load(connector, edidname, connector_name);
>>  +	kfree(edidname);
>> 
>>   	return edid;
>>   }
>>  diff --git a/include/drm/drm_connector.h 
>> b/include/drm/drm_connector.h
>>  index 3ac4bf87f257..47c84741517e 100644
>>  --- a/include/drm/drm_connector.h
>>  +++ b/include/drm/drm_connector.h
>>  @@ -1573,6 +1573,18 @@ struct drm_connector {
>>   	 */
>>   	struct i2c_adapter *ddc;
>> 
>>  +	/**
>>  +	 * @edid_load_pdev: Platform device for loading EDID via firmware.
>>  +	 *
>>  +	 * The platform device is registered in drm_connector_init() in 
>> case a
>>  +	 * custom EDID firmware is used with `edid_firmware` parameter. 
>> Otherwise,
>>  +	 * it is set to NULL.
>>  +	 *
>>  +	 * Platform device is unregistered in drm_connector_cleanup() if 
>> it
>>  +	 * is not NULL.
>>  +	 */
>>  +	struct platform_device *edid_load_pdev;
>>  +
>>   	/**
>>   	 * @null_edid_counter: track sinks that give us all zeros for the 
>> EDID.
>>   	 * Needed to workaround some HW bugs where we get all 0s
>>  diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
>>  index b2756753370b..e907c928a35d 100644
>>  --- a/include/drm/drm_edid.h
>>  +++ b/include/drm/drm_edid.h
>>  @@ -378,10 +378,13 @@ int drm_av_sync_delay(struct drm_connector 
>> *connector,
>>   		      const struct drm_display_mode *mode);
>> 
>>   #ifdef CONFIG_DRM_LOAD_EDID_FIRMWARE
>>  +void drm_cache_edid_firmware(struct drm_connector *connector);
>>   struct edid *drm_load_edid_firmware(struct drm_connector 
>> *connector);
>>   int __drm_set_edid_firmware_path(const char *path);
>>   int __drm_get_edid_firmware_path(char *buf, size_t bufsize);
>>   #else
>>  +inline void
>>  +drm_cache_edid_firmware(struct drm_connector *connector);
>>   static inline struct edid *
>>   drm_load_edid_firmware(struct drm_connector *connector)
>>   {
> 
> --
> Jani Nikula, Intel Open Source Graphics Center
Jani Nikula Aug. 8, 2022, 5:19 p.m. UTC | #6
On Mon, 08 Aug 2022, Matthieu CHARETTE <matthieu.charette@gmail.com> wrote:
> Sorry, What do you mean?

You cache with one name at connector init time, but the name specified
using drm.edid_firmware may be changed whenever, to cause the next EDID
read to use a different EDID firmware.

BR,
Jani.


>
> Matthieu
>
> On Tue, Aug 2 2022 at 05:29:12 PM +0300, Jani Nikula 
> <jani.nikula@linux.intel.com> wrote:
>> On Wed, 27 Jul 2022, Matthieu CHARETTE <matthieu.charette@gmail.com 
>> <mailto:matthieu.charette@gmail.com>> wrote:
>>>  Loading an EDID using drm.edid_firmware parameter makes resume to 
>>> fail
>>>  after firmware cache is being cleaned. This is because edid_load() 
>>> use a
>>>  temporary device to request the firmware. This cause the EDID 
>>> firmware
>>>  not to be cached from suspend. And, requesting the EDID firmware 
>>> return
>>>  an error during resume.
>>>  So the request_firmware() call should use a permanent device for 
>>> each
>>>  connector. Also, we should cache the EDID even if no monitor is
>>>  connected, in case it's plugged while suspended.
>> 
>> AFAICT this breaks changing drm.edid_firmware runtime.
>> 
>> BR,
>> Jani.
>> 
>>> 
>>>  Link: <https://gitlab.freedesktop.org/drm/amd/-/issues/2061>
>>>  Signed-off-by: Matthieu CHARETTE <matthieu.charette@gmail.com 
>>> <mailto:matthieu.charette@gmail.com>>
>>>  ---
>>>   drivers/gpu/drm/drm_connector.c |  9 ++++
>>>   drivers/gpu/drm/drm_edid_load.c | 81 
>>> ++++++++++++++++++++++++++++-----
>>>   include/drm/drm_connector.h     | 12 +++++
>>>   include/drm/drm_edid.h          |  3 ++
>>>   4 files changed, 94 insertions(+), 11 deletions(-)
>>> 
>>>  diff --git a/drivers/gpu/drm/drm_connector.c 
>>> b/drivers/gpu/drm/drm_connector.c
>>>  index 1c48d162c77e..e8819ebf1c4b 100644
>>>  --- a/drivers/gpu/drm/drm_connector.c
>>>  +++ b/drivers/gpu/drm/drm_connector.c
>>>  @@ -31,6 +31,7 @@
>>>   #include <drm/drm_privacy_screen_consumer.h>
>>>   #include <drm/drm_sysfs.h>
>>> 
>>>  +#include <linux/platform_device.h>
>>>   #include <linux/uaccess.h>
>>> 
>>>   #include "drm_crtc_internal.h"
>>>  @@ -289,6 +290,9 @@ int drm_connector_init(struct drm_device *dev,
>>> 
>>>   	drm_connector_get_cmdline_mode(connector);
>>> 
>>>  +	connector->edid_load_pdev = NULL;
>>>  +	drm_cache_edid_firmware(connector);
>>>  +
>>>   	/* We should add connectors at the end to avoid upsetting the 
>>> connector
>>>   	 * index too much.
>>>   	 */
>>>  @@ -473,6 +477,11 @@ void drm_connector_cleanup(struct 
>>> drm_connector *connector)
>>>   		connector->tile_group = NULL;
>>>   	}
>>> 
>>>  +	if (connector->edid_load_pdev) {
>>>  +		platform_device_unregister(connector->edid_load_pdev);
>>>  +		connector->edid_load_pdev = NULL;
>>>  +	}
>>>  +
>>>   	list_for_each_entry_safe(mode, t, &connector->probed_modes, head)
>>>   		drm_mode_remove(connector, mode);
>>> 
>>>  diff --git a/drivers/gpu/drm/drm_edid_load.c 
>>> b/drivers/gpu/drm/drm_edid_load.c
>>>  index 37d8ba3ddb46..5a82be9917ec 100644
>>>  --- a/drivers/gpu/drm/drm_edid_load.c
>>>  +++ b/drivers/gpu/drm/drm_edid_load.c
>>>  @@ -167,6 +167,19 @@ static int edid_size(const u8 *edid, int 
>>> data_size)
>>>   	return (edid[0x7e] + 1) * EDID_LENGTH;
>>>   }
>>> 
>>>  +static struct platform_device *edid_pdev(const char 
>>> *connector_name)
>>>  +{
>>>  +	struct platform_device *pdev = 
>>> platform_device_register_simple(connector_name, -1, NULL, 0);
>>>  +
>>>  +	if (IS_ERR(pdev)) {
>>>  +		DRM_ERROR("Failed to register EDID firmware platform device "
>>>  +			"for connector \"%s\"\n", connector_name);
>>>  +		return ERR_CAST(pdev);
>>>  +	}
>>>  +
>>>  +	return pdev;
>>>  +}
>>>  +
>>>   static void *edid_load(struct drm_connector *connector, const char 
>>> *name,
>>>   			const char *connector_name)
>>>   {
>>>  @@ -182,18 +195,17 @@ static void *edid_load(struct drm_connector 
>>> *connector, const char *name,
>>>   		fwdata = generic_edid[builtin];
>>>   		fwsize = sizeof(generic_edid[builtin]);
>>>   	} else {
>>>  -		struct platform_device *pdev;
>>>  +		struct platform_device *pdev = connector->edid_load_pdev;
>>>   		int err;
>>> 
>>>  -		pdev = platform_device_register_simple(connector_name, -1, NULL, 
>>> 0);
>>>  -		if (IS_ERR(pdev)) {
>>>  -			DRM_ERROR("Failed to register EDID firmware platform device "
>>>  -				  "for connector \"%s\"\n", connector_name);
>>>  -			return ERR_CAST(pdev);
>>>  +		if (WARN_ON(!pdev)) {
>>>  +			pdev = edid_pdev(connector_name);
>>>  +			if (IS_ERR(pdev))
>>>  +				return ERR_CAST(pdev);
>>>  +			connector->edid_load_pdev = pdev;
>>>   		}
>>> 
>>>   		err = request_firmware(&fw, name, &pdev->dev);
>>>  -		platform_device_unregister(pdev);
>>>   		if (err) {
>>>   			DRM_ERROR("Requesting EDID firmware \"%s\" failed (err=%d)\n",
>>>   				  name, err);
>>>  @@ -263,11 +275,9 @@ static void *edid_load(struct drm_connector 
>>> *connector, const char *name,
>>>   	return edid;
>>>   }
>>> 
>>>  -struct edid *drm_load_edid_firmware(struct drm_connector 
>>> *connector)
>>>  +static char *edid_name(const char *connector_name)
>>>   {
>>>  -	const char *connector_name = connector->name;
>>>   	char *edidname, *last, *colon, *fwstr, *edidstr, *fallback = NULL;
>>>  -	struct edid *edid;
>>> 
>>>   	if (edid_firmware[0] == '\0')
>>>   		return ERR_PTR(-ENOENT);
>>>  @@ -310,8 +320,57 @@ struct edid *drm_load_edid_firmware(struct 
>>> drm_connector *connector)
>>>   	if (*last == '\n')
>>>   		*last = '\0';
>>> 
>>>  -	edid = edid_load(connector, edidname, connector_name);
>>>  +	edidname = kstrdup(edidname, GFP_KERNEL);
>>>  +	if (!edidname) {
>>>  +		kfree(fwstr);
>>>  +		return ERR_PTR(-ENOMEM);
>>>  +	}
>>>  +
>>>   	kfree(fwstr);
>>>  +	return edidname;
>>>  +}
>>>  +
>>>  +void drm_cache_edid_firmware(struct drm_connector *connector)
>>>  +{
>>>  +	const char *connector_name = connector->name;
>>>  +	const char *edidname = edid_name(connector_name);
>>>  +	struct platform_device *pdev;
>>>  +	int err;
>>>  +
>>>  +	if (IS_ERR(edidname))
>>>  +		return;
>>>  +
>>>  +	if (match_string(generic_edid_name, GENERIC_EDIDS, edidname) >= 
>>> 0) {
>>>  +		kfree(edidname);
>>>  +		return;
>>>  +	}
>>>  +
>>>  +	pdev = edid_pdev(connector_name);
>>>  +	if (IS_ERR(pdev)) {
>>>  +		kfree(edidname);
>>>  +		return;
>>>  +	}
>>>  +	connector->edid_load_pdev = pdev;
>>>  +
>>>  +	err = firmware_request_cache(&pdev->dev, edidname);
>>>  +	if (err)
>>>  +		DRM_ERROR("Requesting EDID firmware cache \"%s\" failed 
>>> (err=%d)\n",
>>>  +			edidname, err);
>>>  +
>>>  +	kfree(edidname);
>>>  +}
>>>  +
>>>  +struct edid *drm_load_edid_firmware(struct drm_connector 
>>> *connector)
>>>  +{
>>>  +	const char *connector_name = connector->name;
>>>  +	const char *edidname = edid_name(connector_name);
>>>  +	struct edid *edid;
>>>  +
>>>  +	if (IS_ERR(edidname))
>>>  +		return ERR_CAST(edidname);
>>>  +
>>>  +	edid = edid_load(connector, edidname, connector_name);
>>>  +	kfree(edidname);
>>> 
>>>   	return edid;
>>>   }
>>>  diff --git a/include/drm/drm_connector.h 
>>> b/include/drm/drm_connector.h
>>>  index 3ac4bf87f257..47c84741517e 100644
>>>  --- a/include/drm/drm_connector.h
>>>  +++ b/include/drm/drm_connector.h
>>>  @@ -1573,6 +1573,18 @@ struct drm_connector {
>>>   	 */
>>>   	struct i2c_adapter *ddc;
>>> 
>>>  +	/**
>>>  +	 * @edid_load_pdev: Platform device for loading EDID via firmware.
>>>  +	 *
>>>  +	 * The platform device is registered in drm_connector_init() in 
>>> case a
>>>  +	 * custom EDID firmware is used with `edid_firmware` parameter. 
>>> Otherwise,
>>>  +	 * it is set to NULL.
>>>  +	 *
>>>  +	 * Platform device is unregistered in drm_connector_cleanup() if 
>>> it
>>>  +	 * is not NULL.
>>>  +	 */
>>>  +	struct platform_device *edid_load_pdev;
>>>  +
>>>   	/**
>>>   	 * @null_edid_counter: track sinks that give us all zeros for the 
>>> EDID.
>>>   	 * Needed to workaround some HW bugs where we get all 0s
>>>  diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
>>>  index b2756753370b..e907c928a35d 100644
>>>  --- a/include/drm/drm_edid.h
>>>  +++ b/include/drm/drm_edid.h
>>>  @@ -378,10 +378,13 @@ int drm_av_sync_delay(struct drm_connector 
>>> *connector,
>>>   		      const struct drm_display_mode *mode);
>>> 
>>>   #ifdef CONFIG_DRM_LOAD_EDID_FIRMWARE
>>>  +void drm_cache_edid_firmware(struct drm_connector *connector);
>>>   struct edid *drm_load_edid_firmware(struct drm_connector 
>>> *connector);
>>>   int __drm_set_edid_firmware_path(const char *path);
>>>   int __drm_get_edid_firmware_path(char *buf, size_t bufsize);
>>>   #else
>>>  +inline void
>>>  +drm_cache_edid_firmware(struct drm_connector *connector);
>>>   static inline struct edid *
>>>   drm_load_edid_firmware(struct drm_connector *connector)
>>>   {
>> 
>> --
>> Jani Nikula, Intel Open Source Graphics Center
>
Matthieu CHARETTE Sept. 12, 2022, 4:25 p.m. UTC | #7
Hi,

Sorry for late reply.

How do you propose to go then?
Can we still use a persistent platform device to load the firmware and 
cache it? But, in this case the system will still crash in case the 
user change drm.edid_firmware then, without replugging the device, he 
suspends and resumes the machine.
Or you may have a better idea?

Thanks,
Matthieu

On Mon, Aug 8 2022 at 08:19:01 PM +0300, Jani Nikula 
<jani.nikula@linux.intel.com> wrote:
> On Mon, 08 Aug 2022, Matthieu CHARETTE <matthieu.charette@gmail.com> 
> wrote:
>>  Sorry, What do you mean?
> 
> You cache with one name at connector init time, but the name specified
> using drm.edid_firmware may be changed whenever, to cause the next 
> EDID
> read to use a different EDID firmware.
> 
> BR,
> Jani.
> 
> 
>> 
>>  Matthieu
>> 
>>  On Tue, Aug 2 2022 at 05:29:12 PM +0300, Jani Nikula
>>  <jani.nikula@linux.intel.com> wrote:
>>>  On Wed, 27 Jul 2022, Matthieu CHARETTE <matthieu.charette@gmail.com
>>>  <mailto:matthieu.charette@gmail.com>> wrote:
>>>>   Loading an EDID using drm.edid_firmware parameter makes resume to
>>>>  fail
>>>>   after firmware cache is being cleaned. This is because 
>>>> edid_load()
>>>>  use a
>>>>   temporary device to request the firmware. This cause the EDID
>>>>  firmware
>>>>   not to be cached from suspend. And, requesting the EDID firmware
>>>>  return
>>>>   an error during resume.
>>>>   So the request_firmware() call should use a permanent device for
>>>>  each
>>>>   connector. Also, we should cache the EDID even if no monitor is
>>>>   connected, in case it's plugged while suspended.
>>> 
>>>  AFAICT this breaks changing drm.edid_firmware runtime.
>>> 
>>>  BR,
>>>  Jani.
>>> 
>>>> 
>>>>   Link: <https://gitlab.freedesktop.org/drm/amd/-/issues/2061>
>>>>   Signed-off-by: Matthieu CHARETTE <matthieu.charette@gmail.com
>>>>  <mailto:matthieu.charette@gmail.com>>
>>>>   ---
>>>>    drivers/gpu/drm/drm_connector.c |  9 ++++
>>>>    drivers/gpu/drm/drm_edid_load.c | 81
>>>>  ++++++++++++++++++++++++++++-----
>>>>    include/drm/drm_connector.h     | 12 +++++
>>>>    include/drm/drm_edid.h          |  3 ++
>>>>    4 files changed, 94 insertions(+), 11 deletions(-)
>>>> 
>>>>   diff --git a/drivers/gpu/drm/drm_connector.c
>>>>  b/drivers/gpu/drm/drm_connector.c
>>>>   index 1c48d162c77e..e8819ebf1c4b 100644
>>>>   --- a/drivers/gpu/drm/drm_connector.c
>>>>   +++ b/drivers/gpu/drm/drm_connector.c
>>>>   @@ -31,6 +31,7 @@
>>>>    #include <drm/drm_privacy_screen_consumer.h>
>>>>    #include <drm/drm_sysfs.h>
>>>> 
>>>>   +#include <linux/platform_device.h>
>>>>    #include <linux/uaccess.h>
>>>> 
>>>>    #include "drm_crtc_internal.h"
>>>>   @@ -289,6 +290,9 @@ int drm_connector_init(struct drm_device 
>>>> *dev,
>>>> 
>>>>    	drm_connector_get_cmdline_mode(connector);
>>>> 
>>>>   +	connector->edid_load_pdev = NULL;
>>>>   +	drm_cache_edid_firmware(connector);
>>>>   +
>>>>    	/* We should add connectors at the end to avoid upsetting the
>>>>  connector
>>>>    	 * index too much.
>>>>    	 */
>>>>   @@ -473,6 +477,11 @@ void drm_connector_cleanup(struct
>>>>  drm_connector *connector)
>>>>    		connector->tile_group = NULL;
>>>>    	}
>>>> 
>>>>   +	if (connector->edid_load_pdev) {
>>>>   +		platform_device_unregister(connector->edid_load_pdev);
>>>>   +		connector->edid_load_pdev = NULL;
>>>>   +	}
>>>>   +
>>>>    	list_for_each_entry_safe(mode, t, &connector->probed_modes, 
>>>> head)
>>>>    		drm_mode_remove(connector, mode);
>>>> 
>>>>   diff --git a/drivers/gpu/drm/drm_edid_load.c
>>>>  b/drivers/gpu/drm/drm_edid_load.c
>>>>   index 37d8ba3ddb46..5a82be9917ec 100644
>>>>   --- a/drivers/gpu/drm/drm_edid_load.c
>>>>   +++ b/drivers/gpu/drm/drm_edid_load.c
>>>>   @@ -167,6 +167,19 @@ static int edid_size(const u8 *edid, int
>>>>  data_size)
>>>>    	return (edid[0x7e] + 1) * EDID_LENGTH;
>>>>    }
>>>> 
>>>>   +static struct platform_device *edid_pdev(const char
>>>>  *connector_name)
>>>>   +{
>>>>   +	struct platform_device *pdev =
>>>>  platform_device_register_simple(connector_name, -1, NULL, 0);
>>>>   +
>>>>   +	if (IS_ERR(pdev)) {
>>>>   +		DRM_ERROR("Failed to register EDID firmware platform device "
>>>>   +			"for connector \"%s\"\n", connector_name);
>>>>   +		return ERR_CAST(pdev);
>>>>   +	}
>>>>   +
>>>>   +	return pdev;
>>>>   +}
>>>>   +
>>>>    static void *edid_load(struct drm_connector *connector, const 
>>>> char
>>>>  *name,
>>>>    			const char *connector_name)
>>>>    {
>>>>   @@ -182,18 +195,17 @@ static void *edid_load(struct drm_connector
>>>>  *connector, const char *name,
>>>>    		fwdata = generic_edid[builtin];
>>>>    		fwsize = sizeof(generic_edid[builtin]);
>>>>    	} else {
>>>>   -		struct platform_device *pdev;
>>>>   +		struct platform_device *pdev = connector->edid_load_pdev;
>>>>    		int err;
>>>> 
>>>>   -		pdev = platform_device_register_simple(connector_name, -1, 
>>>> NULL,
>>>>  0);
>>>>   -		if (IS_ERR(pdev)) {
>>>>   -			DRM_ERROR("Failed to register EDID firmware platform device "
>>>>   -				  "for connector \"%s\"\n", connector_name);
>>>>   -			return ERR_CAST(pdev);
>>>>   +		if (WARN_ON(!pdev)) {
>>>>   +			pdev = edid_pdev(connector_name);
>>>>   +			if (IS_ERR(pdev))
>>>>   +				return ERR_CAST(pdev);
>>>>   +			connector->edid_load_pdev = pdev;
>>>>    		}
>>>> 
>>>>    		err = request_firmware(&fw, name, &pdev->dev);
>>>>   -		platform_device_unregister(pdev);
>>>>    		if (err) {
>>>>    			DRM_ERROR("Requesting EDID firmware \"%s\" failed 
>>>> (err=%d)\n",
>>>>    				  name, err);
>>>>   @@ -263,11 +275,9 @@ static void *edid_load(struct drm_connector
>>>>  *connector, const char *name,
>>>>    	return edid;
>>>>    }
>>>> 
>>>>   -struct edid *drm_load_edid_firmware(struct drm_connector
>>>>  *connector)
>>>>   +static char *edid_name(const char *connector_name)
>>>>    {
>>>>   -	const char *connector_name = connector->name;
>>>>    	char *edidname, *last, *colon, *fwstr, *edidstr, *fallback = 
>>>> NULL;
>>>>   -	struct edid *edid;
>>>> 
>>>>    	if (edid_firmware[0] == '\0')
>>>>    		return ERR_PTR(-ENOENT);
>>>>   @@ -310,8 +320,57 @@ struct edid *drm_load_edid_firmware(struct
>>>>  drm_connector *connector)
>>>>    	if (*last == '\n')
>>>>    		*last = '\0';
>>>> 
>>>>   -	edid = edid_load(connector, edidname, connector_name);
>>>>   +	edidname = kstrdup(edidname, GFP_KERNEL);
>>>>   +	if (!edidname) {
>>>>   +		kfree(fwstr);
>>>>   +		return ERR_PTR(-ENOMEM);
>>>>   +	}
>>>>   +
>>>>    	kfree(fwstr);
>>>>   +	return edidname;
>>>>   +}
>>>>   +
>>>>   +void drm_cache_edid_firmware(struct drm_connector *connector)
>>>>   +{
>>>>   +	const char *connector_name = connector->name;
>>>>   +	const char *edidname = edid_name(connector_name);
>>>>   +	struct platform_device *pdev;
>>>>   +	int err;
>>>>   +
>>>>   +	if (IS_ERR(edidname))
>>>>   +		return;
>>>>   +
>>>>   +	if (match_string(generic_edid_name, GENERIC_EDIDS, edidname) >=
>>>>  0) {
>>>>   +		kfree(edidname);
>>>>   +		return;
>>>>   +	}
>>>>   +
>>>>   +	pdev = edid_pdev(connector_name);
>>>>   +	if (IS_ERR(pdev)) {
>>>>   +		kfree(edidname);
>>>>   +		return;
>>>>   +	}
>>>>   +	connector->edid_load_pdev = pdev;
>>>>   +
>>>>   +	err = firmware_request_cache(&pdev->dev, edidname);
>>>>   +	if (err)
>>>>   +		DRM_ERROR("Requesting EDID firmware cache \"%s\" failed
>>>>  (err=%d)\n",
>>>>   +			edidname, err);
>>>>   +
>>>>   +	kfree(edidname);
>>>>   +}
>>>>   +
>>>>   +struct edid *drm_load_edid_firmware(struct drm_connector
>>>>  *connector)
>>>>   +{
>>>>   +	const char *connector_name = connector->name;
>>>>   +	const char *edidname = edid_name(connector_name);
>>>>   +	struct edid *edid;
>>>>   +
>>>>   +	if (IS_ERR(edidname))
>>>>   +		return ERR_CAST(edidname);
>>>>   +
>>>>   +	edid = edid_load(connector, edidname, connector_name);
>>>>   +	kfree(edidname);
>>>> 
>>>>    	return edid;
>>>>    }
>>>>   diff --git a/include/drm/drm_connector.h
>>>>  b/include/drm/drm_connector.h
>>>>   index 3ac4bf87f257..47c84741517e 100644
>>>>   --- a/include/drm/drm_connector.h
>>>>   +++ b/include/drm/drm_connector.h
>>>>   @@ -1573,6 +1573,18 @@ struct drm_connector {
>>>>    	 */
>>>>    	struct i2c_adapter *ddc;
>>>> 
>>>>   +	/**
>>>>   +	 * @edid_load_pdev: Platform device for loading EDID via 
>>>> firmware.
>>>>   +	 *
>>>>   +	 * The platform device is registered in drm_connector_init() in
>>>>  case a
>>>>   +	 * custom EDID firmware is used with `edid_firmware` parameter.
>>>>  Otherwise,
>>>>   +	 * it is set to NULL.
>>>>   +	 *
>>>>   +	 * Platform device is unregistered in drm_connector_cleanup() 
>>>> if
>>>>  it
>>>>   +	 * is not NULL.
>>>>   +	 */
>>>>   +	struct platform_device *edid_load_pdev;
>>>>   +
>>>>    	/**
>>>>    	 * @null_edid_counter: track sinks that give us all zeros for 
>>>> the
>>>>  EDID.
>>>>    	 * Needed to workaround some HW bugs where we get all 0s
>>>>   diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
>>>>   index b2756753370b..e907c928a35d 100644
>>>>   --- a/include/drm/drm_edid.h
>>>>   +++ b/include/drm/drm_edid.h
>>>>   @@ -378,10 +378,13 @@ int drm_av_sync_delay(struct drm_connector
>>>>  *connector,
>>>>    		      const struct drm_display_mode *mode);
>>>> 
>>>>    #ifdef CONFIG_DRM_LOAD_EDID_FIRMWARE
>>>>   +void drm_cache_edid_firmware(struct drm_connector *connector);
>>>>    struct edid *drm_load_edid_firmware(struct drm_connector
>>>>  *connector);
>>>>    int __drm_set_edid_firmware_path(const char *path);
>>>>    int __drm_get_edid_firmware_path(char *buf, size_t bufsize);
>>>>    #else
>>>>   +inline void
>>>>   +drm_cache_edid_firmware(struct drm_connector *connector);
>>>>    static inline struct edid *
>>>>    drm_load_edid_firmware(struct drm_connector *connector)
>>>>    {
>>> 
>>>  --
>>>  Jani Nikula, Intel Open Source Graphics Center
>> 
> 
> --
> Jani Nikula, Intel Open Source Graphics Center
Jani Nikula Oct. 6, 2022, 10:23 p.m. UTC | #8
On Mon, 12 Sep 2022, Matthieu CHARETTE <matthieu.charette@gmail.com> wrote:
> Hi,
>
> Sorry for late reply.
>
> How do you propose to go then?
> Can we still use a persistent platform device to load the firmware and 
> cache it? But, in this case the system will still crash in case the 
> user change drm.edid_firmware then, without replugging the device, he 
> suspends and resumes the machine.
> Or you may have a better idea?

Maybe. Please try [1]. Could it be as simple as that?


BR,
Jani.


[1] https://patchwork.freedesktop.org/patch/msgid/20221006222146.2375217-1-jani.nikula@intel.com

>
> Thanks,
> Matthieu
>
> On Mon, Aug 8 2022 at 08:19:01 PM +0300, Jani Nikula 
> <jani.nikula@linux.intel.com> wrote:
>> On Mon, 08 Aug 2022, Matthieu CHARETTE <matthieu.charette@gmail.com> 
>> wrote:
>>>  Sorry, What do you mean?
>> 
>> You cache with one name at connector init time, but the name specified
>> using drm.edid_firmware may be changed whenever, to cause the next 
>> EDID
>> read to use a different EDID firmware.
>> 
>> BR,
>> Jani.
>> 
>> 
>>> 
>>>  Matthieu
>>> 
>>>  On Tue, Aug 2 2022 at 05:29:12 PM +0300, Jani Nikula
>>>  <jani.nikula@linux.intel.com> wrote:
>>>>  On Wed, 27 Jul 2022, Matthieu CHARETTE <matthieu.charette@gmail.com
>>>>  <mailto:matthieu.charette@gmail.com>> wrote:
>>>>>   Loading an EDID using drm.edid_firmware parameter makes resume to
>>>>>  fail
>>>>>   after firmware cache is being cleaned. This is because 
>>>>> edid_load()
>>>>>  use a
>>>>>   temporary device to request the firmware. This cause the EDID
>>>>>  firmware
>>>>>   not to be cached from suspend. And, requesting the EDID firmware
>>>>>  return
>>>>>   an error during resume.
>>>>>   So the request_firmware() call should use a permanent device for
>>>>>  each
>>>>>   connector. Also, we should cache the EDID even if no monitor is
>>>>>   connected, in case it's plugged while suspended.
>>>> 
>>>>  AFAICT this breaks changing drm.edid_firmware runtime.
>>>> 
>>>>  BR,
>>>>  Jani.
>>>> 
>>>>> 
>>>>>   Link: <https://gitlab.freedesktop.org/drm/amd/-/issues/2061>
>>>>>   Signed-off-by: Matthieu CHARETTE <matthieu.charette@gmail.com
>>>>>  <mailto:matthieu.charette@gmail.com>>
>>>>>   ---
>>>>>    drivers/gpu/drm/drm_connector.c |  9 ++++
>>>>>    drivers/gpu/drm/drm_edid_load.c | 81
>>>>>  ++++++++++++++++++++++++++++-----
>>>>>    include/drm/drm_connector.h     | 12 +++++
>>>>>    include/drm/drm_edid.h          |  3 ++
>>>>>    4 files changed, 94 insertions(+), 11 deletions(-)
>>>>> 
>>>>>   diff --git a/drivers/gpu/drm/drm_connector.c
>>>>>  b/drivers/gpu/drm/drm_connector.c
>>>>>   index 1c48d162c77e..e8819ebf1c4b 100644
>>>>>   --- a/drivers/gpu/drm/drm_connector.c
>>>>>   +++ b/drivers/gpu/drm/drm_connector.c
>>>>>   @@ -31,6 +31,7 @@
>>>>>    #include <drm/drm_privacy_screen_consumer.h>
>>>>>    #include <drm/drm_sysfs.h>
>>>>> 
>>>>>   +#include <linux/platform_device.h>
>>>>>    #include <linux/uaccess.h>
>>>>> 
>>>>>    #include "drm_crtc_internal.h"
>>>>>   @@ -289,6 +290,9 @@ int drm_connector_init(struct drm_device 
>>>>> *dev,
>>>>> 
>>>>>    	drm_connector_get_cmdline_mode(connector);
>>>>> 
>>>>>   +	connector->edid_load_pdev = NULL;
>>>>>   +	drm_cache_edid_firmware(connector);
>>>>>   +
>>>>>    	/* We should add connectors at the end to avoid upsetting the
>>>>>  connector
>>>>>    	 * index too much.
>>>>>    	 */
>>>>>   @@ -473,6 +477,11 @@ void drm_connector_cleanup(struct
>>>>>  drm_connector *connector)
>>>>>    		connector->tile_group = NULL;
>>>>>    	}
>>>>> 
>>>>>   +	if (connector->edid_load_pdev) {
>>>>>   +		platform_device_unregister(connector->edid_load_pdev);
>>>>>   +		connector->edid_load_pdev = NULL;
>>>>>   +	}
>>>>>   +
>>>>>    	list_for_each_entry_safe(mode, t, &connector->probed_modes, 
>>>>> head)
>>>>>    		drm_mode_remove(connector, mode);
>>>>> 
>>>>>   diff --git a/drivers/gpu/drm/drm_edid_load.c
>>>>>  b/drivers/gpu/drm/drm_edid_load.c
>>>>>   index 37d8ba3ddb46..5a82be9917ec 100644
>>>>>   --- a/drivers/gpu/drm/drm_edid_load.c
>>>>>   +++ b/drivers/gpu/drm/drm_edid_load.c
>>>>>   @@ -167,6 +167,19 @@ static int edid_size(const u8 *edid, int
>>>>>  data_size)
>>>>>    	return (edid[0x7e] + 1) * EDID_LENGTH;
>>>>>    }
>>>>> 
>>>>>   +static struct platform_device *edid_pdev(const char
>>>>>  *connector_name)
>>>>>   +{
>>>>>   +	struct platform_device *pdev =
>>>>>  platform_device_register_simple(connector_name, -1, NULL, 0);
>>>>>   +
>>>>>   +	if (IS_ERR(pdev)) {
>>>>>   +		DRM_ERROR("Failed to register EDID firmware platform device "
>>>>>   +			"for connector \"%s\"\n", connector_name);
>>>>>   +		return ERR_CAST(pdev);
>>>>>   +	}
>>>>>   +
>>>>>   +	return pdev;
>>>>>   +}
>>>>>   +
>>>>>    static void *edid_load(struct drm_connector *connector, const 
>>>>> char
>>>>>  *name,
>>>>>    			const char *connector_name)
>>>>>    {
>>>>>   @@ -182,18 +195,17 @@ static void *edid_load(struct drm_connector
>>>>>  *connector, const char *name,
>>>>>    		fwdata = generic_edid[builtin];
>>>>>    		fwsize = sizeof(generic_edid[builtin]);
>>>>>    	} else {
>>>>>   -		struct platform_device *pdev;
>>>>>   +		struct platform_device *pdev = connector->edid_load_pdev;
>>>>>    		int err;
>>>>> 
>>>>>   -		pdev = platform_device_register_simple(connector_name, -1, 
>>>>> NULL,
>>>>>  0);
>>>>>   -		if (IS_ERR(pdev)) {
>>>>>   -			DRM_ERROR("Failed to register EDID firmware platform device "
>>>>>   -				  "for connector \"%s\"\n", connector_name);
>>>>>   -			return ERR_CAST(pdev);
>>>>>   +		if (WARN_ON(!pdev)) {
>>>>>   +			pdev = edid_pdev(connector_name);
>>>>>   +			if (IS_ERR(pdev))
>>>>>   +				return ERR_CAST(pdev);
>>>>>   +			connector->edid_load_pdev = pdev;
>>>>>    		}
>>>>> 
>>>>>    		err = request_firmware(&fw, name, &pdev->dev);
>>>>>   -		platform_device_unregister(pdev);
>>>>>    		if (err) {
>>>>>    			DRM_ERROR("Requesting EDID firmware \"%s\" failed 
>>>>> (err=%d)\n",
>>>>>    				  name, err);
>>>>>   @@ -263,11 +275,9 @@ static void *edid_load(struct drm_connector
>>>>>  *connector, const char *name,
>>>>>    	return edid;
>>>>>    }
>>>>> 
>>>>>   -struct edid *drm_load_edid_firmware(struct drm_connector
>>>>>  *connector)
>>>>>   +static char *edid_name(const char *connector_name)
>>>>>    {
>>>>>   -	const char *connector_name = connector->name;
>>>>>    	char *edidname, *last, *colon, *fwstr, *edidstr, *fallback = 
>>>>> NULL;
>>>>>   -	struct edid *edid;
>>>>> 
>>>>>    	if (edid_firmware[0] == '\0')
>>>>>    		return ERR_PTR(-ENOENT);
>>>>>   @@ -310,8 +320,57 @@ struct edid *drm_load_edid_firmware(struct
>>>>>  drm_connector *connector)
>>>>>    	if (*last == '\n')
>>>>>    		*last = '\0';
>>>>> 
>>>>>   -	edid = edid_load(connector, edidname, connector_name);
>>>>>   +	edidname = kstrdup(edidname, GFP_KERNEL);
>>>>>   +	if (!edidname) {
>>>>>   +		kfree(fwstr);
>>>>>   +		return ERR_PTR(-ENOMEM);
>>>>>   +	}
>>>>>   +
>>>>>    	kfree(fwstr);
>>>>>   +	return edidname;
>>>>>   +}
>>>>>   +
>>>>>   +void drm_cache_edid_firmware(struct drm_connector *connector)
>>>>>   +{
>>>>>   +	const char *connector_name = connector->name;
>>>>>   +	const char *edidname = edid_name(connector_name);
>>>>>   +	struct platform_device *pdev;
>>>>>   +	int err;
>>>>>   +
>>>>>   +	if (IS_ERR(edidname))
>>>>>   +		return;
>>>>>   +
>>>>>   +	if (match_string(generic_edid_name, GENERIC_EDIDS, edidname) >=
>>>>>  0) {
>>>>>   +		kfree(edidname);
>>>>>   +		return;
>>>>>   +	}
>>>>>   +
>>>>>   +	pdev = edid_pdev(connector_name);
>>>>>   +	if (IS_ERR(pdev)) {
>>>>>   +		kfree(edidname);
>>>>>   +		return;
>>>>>   +	}
>>>>>   +	connector->edid_load_pdev = pdev;
>>>>>   +
>>>>>   +	err = firmware_request_cache(&pdev->dev, edidname);
>>>>>   +	if (err)
>>>>>   +		DRM_ERROR("Requesting EDID firmware cache \"%s\" failed
>>>>>  (err=%d)\n",
>>>>>   +			edidname, err);
>>>>>   +
>>>>>   +	kfree(edidname);
>>>>>   +}
>>>>>   +
>>>>>   +struct edid *drm_load_edid_firmware(struct drm_connector
>>>>>  *connector)
>>>>>   +{
>>>>>   +	const char *connector_name = connector->name;
>>>>>   +	const char *edidname = edid_name(connector_name);
>>>>>   +	struct edid *edid;
>>>>>   +
>>>>>   +	if (IS_ERR(edidname))
>>>>>   +		return ERR_CAST(edidname);
>>>>>   +
>>>>>   +	edid = edid_load(connector, edidname, connector_name);
>>>>>   +	kfree(edidname);
>>>>> 
>>>>>    	return edid;
>>>>>    }
>>>>>   diff --git a/include/drm/drm_connector.h
>>>>>  b/include/drm/drm_connector.h
>>>>>   index 3ac4bf87f257..47c84741517e 100644
>>>>>   --- a/include/drm/drm_connector.h
>>>>>   +++ b/include/drm/drm_connector.h
>>>>>   @@ -1573,6 +1573,18 @@ struct drm_connector {
>>>>>    	 */
>>>>>    	struct i2c_adapter *ddc;
>>>>> 
>>>>>   +	/**
>>>>>   +	 * @edid_load_pdev: Platform device for loading EDID via 
>>>>> firmware.
>>>>>   +	 *
>>>>>   +	 * The platform device is registered in drm_connector_init() in
>>>>>  case a
>>>>>   +	 * custom EDID firmware is used with `edid_firmware` parameter.
>>>>>  Otherwise,
>>>>>   +	 * it is set to NULL.
>>>>>   +	 *
>>>>>   +	 * Platform device is unregistered in drm_connector_cleanup() 
>>>>> if
>>>>>  it
>>>>>   +	 * is not NULL.
>>>>>   +	 */
>>>>>   +	struct platform_device *edid_load_pdev;
>>>>>   +
>>>>>    	/**
>>>>>    	 * @null_edid_counter: track sinks that give us all zeros for 
>>>>> the
>>>>>  EDID.
>>>>>    	 * Needed to workaround some HW bugs where we get all 0s
>>>>>   diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
>>>>>   index b2756753370b..e907c928a35d 100644
>>>>>   --- a/include/drm/drm_edid.h
>>>>>   +++ b/include/drm/drm_edid.h
>>>>>   @@ -378,10 +378,13 @@ int drm_av_sync_delay(struct drm_connector
>>>>>  *connector,
>>>>>    		      const struct drm_display_mode *mode);
>>>>> 
>>>>>    #ifdef CONFIG_DRM_LOAD_EDID_FIRMWARE
>>>>>   +void drm_cache_edid_firmware(struct drm_connector *connector);
>>>>>    struct edid *drm_load_edid_firmware(struct drm_connector
>>>>>  *connector);
>>>>>    int __drm_set_edid_firmware_path(const char *path);
>>>>>    int __drm_get_edid_firmware_path(char *buf, size_t bufsize);
>>>>>    #else
>>>>>   +inline void
>>>>>   +drm_cache_edid_firmware(struct drm_connector *connector);
>>>>>    static inline struct edid *
>>>>>    drm_load_edid_firmware(struct drm_connector *connector)
>>>>>    {
>>>> 
>>>>  --
>>>>  Jani Nikula, Intel Open Source Graphics Center
>>> 
>> 
>> --
>> Jani Nikula, Intel Open Source Graphics Center
>
>
diff mbox series

Patch

diff --git a/drivers/gpu/drm/drm_connector.c b/drivers/gpu/drm/drm_connector.c
index 1c48d162c77e..e8819ebf1c4b 100644
--- a/drivers/gpu/drm/drm_connector.c
+++ b/drivers/gpu/drm/drm_connector.c
@@ -31,6 +31,7 @@ 
 #include <drm/drm_privacy_screen_consumer.h>
 #include <drm/drm_sysfs.h>
 
+#include <linux/platform_device.h>
 #include <linux/uaccess.h>
 
 #include "drm_crtc_internal.h"
@@ -289,6 +290,9 @@  int drm_connector_init(struct drm_device *dev,
 
 	drm_connector_get_cmdline_mode(connector);
 
+	connector->edid_load_pdev = NULL;
+	drm_cache_edid_firmware(connector);
+
 	/* We should add connectors at the end to avoid upsetting the connector
 	 * index too much.
 	 */
@@ -473,6 +477,11 @@  void drm_connector_cleanup(struct drm_connector *connector)
 		connector->tile_group = NULL;
 	}
 
+	if (connector->edid_load_pdev) {
+		platform_device_unregister(connector->edid_load_pdev);
+		connector->edid_load_pdev = NULL;
+	}
+
 	list_for_each_entry_safe(mode, t, &connector->probed_modes, head)
 		drm_mode_remove(connector, mode);
 
diff --git a/drivers/gpu/drm/drm_edid_load.c b/drivers/gpu/drm/drm_edid_load.c
index 37d8ba3ddb46..5a82be9917ec 100644
--- a/drivers/gpu/drm/drm_edid_load.c
+++ b/drivers/gpu/drm/drm_edid_load.c
@@ -167,6 +167,19 @@  static int edid_size(const u8 *edid, int data_size)
 	return (edid[0x7e] + 1) * EDID_LENGTH;
 }
 
+static struct platform_device *edid_pdev(const char *connector_name)
+{
+	struct platform_device *pdev = platform_device_register_simple(connector_name, -1, NULL, 0);
+
+	if (IS_ERR(pdev)) {
+		DRM_ERROR("Failed to register EDID firmware platform device "
+			"for connector \"%s\"\n", connector_name);
+		return ERR_CAST(pdev);
+	}
+
+	return pdev;
+}
+
 static void *edid_load(struct drm_connector *connector, const char *name,
 			const char *connector_name)
 {
@@ -182,18 +195,17 @@  static void *edid_load(struct drm_connector *connector, const char *name,
 		fwdata = generic_edid[builtin];
 		fwsize = sizeof(generic_edid[builtin]);
 	} else {
-		struct platform_device *pdev;
+		struct platform_device *pdev = connector->edid_load_pdev;
 		int err;
 
-		pdev = platform_device_register_simple(connector_name, -1, NULL, 0);
-		if (IS_ERR(pdev)) {
-			DRM_ERROR("Failed to register EDID firmware platform device "
-				  "for connector \"%s\"\n", connector_name);
-			return ERR_CAST(pdev);
+		if (WARN_ON(!pdev)) {
+			pdev = edid_pdev(connector_name);
+			if (IS_ERR(pdev))
+				return ERR_CAST(pdev);
+			connector->edid_load_pdev = pdev;
 		}
 
 		err = request_firmware(&fw, name, &pdev->dev);
-		platform_device_unregister(pdev);
 		if (err) {
 			DRM_ERROR("Requesting EDID firmware \"%s\" failed (err=%d)\n",
 				  name, err);
@@ -263,11 +275,9 @@  static void *edid_load(struct drm_connector *connector, const char *name,
 	return edid;
 }
 
-struct edid *drm_load_edid_firmware(struct drm_connector *connector)
+static char *edid_name(const char *connector_name)
 {
-	const char *connector_name = connector->name;
 	char *edidname, *last, *colon, *fwstr, *edidstr, *fallback = NULL;
-	struct edid *edid;
 
 	if (edid_firmware[0] == '\0')
 		return ERR_PTR(-ENOENT);
@@ -310,8 +320,57 @@  struct edid *drm_load_edid_firmware(struct drm_connector *connector)
 	if (*last == '\n')
 		*last = '\0';
 
-	edid = edid_load(connector, edidname, connector_name);
+	edidname = kstrdup(edidname, GFP_KERNEL);
+	if (!edidname) {
+		kfree(fwstr);
+		return ERR_PTR(-ENOMEM);
+	}
+
 	kfree(fwstr);
+	return edidname;
+}
+
+void drm_cache_edid_firmware(struct drm_connector *connector)
+{
+	const char *connector_name = connector->name;
+	const char *edidname = edid_name(connector_name);
+	struct platform_device *pdev;
+	int err;
+
+	if (IS_ERR(edidname))
+		return;
+
+	if (match_string(generic_edid_name, GENERIC_EDIDS, edidname) >= 0) {
+		kfree(edidname);
+		return;
+	}
+
+	pdev = edid_pdev(connector_name);
+	if (IS_ERR(pdev)) {
+		kfree(edidname);
+		return;
+	}
+	connector->edid_load_pdev = pdev;
+
+	err = firmware_request_cache(&pdev->dev, edidname);
+	if (err)
+		DRM_ERROR("Requesting EDID firmware cache \"%s\" failed (err=%d)\n",
+			edidname, err);
+
+	kfree(edidname);
+}
+
+struct edid *drm_load_edid_firmware(struct drm_connector *connector)
+{
+	const char *connector_name = connector->name;
+	const char *edidname = edid_name(connector_name);
+	struct edid *edid;
+
+	if (IS_ERR(edidname))
+		return ERR_CAST(edidname);
+
+	edid = edid_load(connector, edidname, connector_name);
+	kfree(edidname);
 
 	return edid;
 }
diff --git a/include/drm/drm_connector.h b/include/drm/drm_connector.h
index 3ac4bf87f257..47c84741517e 100644
--- a/include/drm/drm_connector.h
+++ b/include/drm/drm_connector.h
@@ -1573,6 +1573,18 @@  struct drm_connector {
 	 */
 	struct i2c_adapter *ddc;
 
+	/**
+	 * @edid_load_pdev: Platform device for loading EDID via firmware.
+	 *
+	 * The platform device is registered in drm_connector_init() in case a
+	 * custom EDID firmware is used with `edid_firmware` parameter. Otherwise,
+	 * it is set to NULL.
+	 *
+	 * Platform device is unregistered in drm_connector_cleanup() if it
+	 * is not NULL.
+	 */
+	struct platform_device *edid_load_pdev;
+
 	/**
 	 * @null_edid_counter: track sinks that give us all zeros for the EDID.
 	 * Needed to workaround some HW bugs where we get all 0s
diff --git a/include/drm/drm_edid.h b/include/drm/drm_edid.h
index b2756753370b..e907c928a35d 100644
--- a/include/drm/drm_edid.h
+++ b/include/drm/drm_edid.h
@@ -378,10 +378,13 @@  int drm_av_sync_delay(struct drm_connector *connector,
 		      const struct drm_display_mode *mode);
 
 #ifdef CONFIG_DRM_LOAD_EDID_FIRMWARE
+void drm_cache_edid_firmware(struct drm_connector *connector);
 struct edid *drm_load_edid_firmware(struct drm_connector *connector);
 int __drm_set_edid_firmware_path(const char *path);
 int __drm_get_edid_firmware_path(char *buf, size_t bufsize);
 #else
+inline void
+drm_cache_edid_firmware(struct drm_connector *connector);
 static inline struct edid *
 drm_load_edid_firmware(struct drm_connector *connector)
 {