diff mbox series

[v3,02/10] drm/client: Add hotplug_failed flag

Message ID 20230125200415.14123-3-tzimmermann@suse.de (mailing list archive)
State Not Applicable
Headers show
Series drm/fb-helper: Various cleanups | expand

Commit Message

Thomas Zimmermann Jan. 25, 2023, 8:04 p.m. UTC 
Signal failed hotplugging with a flag in struct drm_client_dev. If set,
the client helpers will not further try to set up the fbdev display.

This used to be signalled with a combination of cleared pointers in
struct drm_fb_helper, which prevents us from initializing these pointers
early after allocation.

The change also harmonizes behavior among DRM clients. Additional DRM
clients will now handle failed hotplugging like fbdev does.

Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
---
 drivers/gpu/drm/drm_client.c        | 5 +++++
 drivers/gpu/drm/drm_fbdev_generic.c | 4 ----
 include/drm/drm_client.h            | 8 ++++++++
 3 files changed, 13 insertions(+), 4 deletions(-)

Comments

Sam Ravnborg Jan. 25, 2023, 8:57 p.m. UTC | #1 
Hi Thomas,

On Wed, Jan 25, 2023 at 09:04:07PM +0100, Thomas Zimmermann wrote:
> Signal failed hotplugging with a flag in struct drm_client_dev. If set,
> the client helpers will not further try to set up the fbdev display.
> 
> This used to be signalled with a combination of cleared pointers in
> struct drm_fb_helper,
I failed to find where we clear the pointers. What do I miss?
(I had assumed we would stop clearing the pointers after this change).

	Sam

which prevents us from initializing these pointers
> early after allocation.
> 
> The change also harmonizes behavior among DRM clients. Additional DRM
> clients will now handle failed hotplugging like fbdev does.
> 
> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
> Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
> ---
>  drivers/gpu/drm/drm_client.c        | 5 +++++
>  drivers/gpu/drm/drm_fbdev_generic.c | 4 ----
>  include/drm/drm_client.h            | 8 ++++++++
>  3 files changed, 13 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c
> index 09ac191c202d..009e7b10455c 100644
> --- a/drivers/gpu/drm/drm_client.c
> +++ b/drivers/gpu/drm/drm_client.c
> @@ -208,8 +208,13 @@ void drm_client_dev_hotplug(struct drm_device *dev)
>  		if (!client->funcs || !client->funcs->hotplug)
>  			continue;
>  
> +		if (client->hotplug_failed)
> +			continue;
> +
>  		ret = client->funcs->hotplug(client);
>  		drm_dbg_kms(dev, "%s: ret=%d\n", client->name, ret);
> +		if (ret)
> +			client->hotplug_failed = true;
>  	}
>  	mutex_unlock(&dev->clientlist_mutex);
>  }
> diff --git a/drivers/gpu/drm/drm_fbdev_generic.c b/drivers/gpu/drm/drm_fbdev_generic.c
> index 3d455a2e3fb5..135d58b8007b 100644
> --- a/drivers/gpu/drm/drm_fbdev_generic.c
> +++ b/drivers/gpu/drm/drm_fbdev_generic.c
> @@ -382,10 +382,6 @@ static int drm_fbdev_client_hotplug(struct drm_client_dev *client)
>  	struct drm_device *dev = client->dev;
>  	int ret;
>  
> -	/* Setup is not retried if it has failed */
> -	if (!fb_helper->dev && fb_helper->funcs)
> -		return 0;
> -
>  	if (dev->fb_helper)
>  		return drm_fb_helper_hotplug_event(dev->fb_helper);
>  
> diff --git a/include/drm/drm_client.h b/include/drm/drm_client.h
> index 4fc8018eddda..39482527a775 100644
> --- a/include/drm/drm_client.h
> +++ b/include/drm/drm_client.h
> @@ -106,6 +106,14 @@ struct drm_client_dev {
>  	 * @modesets: CRTC configurations
>  	 */
>  	struct drm_mode_set *modesets;
> +
> +	/**
> +	 * @hotplug failed:
> +	 *
> +	 * Set by client hotplug helpers if the hotplugging failed
> +	 * before. It is usually not tried again.
> +	 */
> +	bool hotplug_failed;
>  };
>  
>  int drm_client_init(struct drm_device *dev, struct drm_client_dev *client,
> -- 
> 2.39.0
Thomas Zimmermann Jan. 27, 2023, 2:17 p.m. UTC | #2 
Hi

Am 25.01.23 um 21:57 schrieb Sam Ravnborg:
> Hi Thomas,
> 
> On Wed, Jan 25, 2023 at 09:04:07PM +0100, Thomas Zimmermann wrote:
>> Signal failed hotplugging with a flag in struct drm_client_dev. If set,
>> the client helpers will not further try to set up the fbdev display.
>>
>> This used to be signalled with a combination of cleared pointers in
>> struct drm_fb_helper,
> I failed to find where we clear the pointers. What do I miss?

Those pointer fields, dev and funcs, where allocated with kzalloc(). The 
error path in drm_fbdev_client_hotplug() later reset them to NULL again 
if an error occured.

Best regards
Thomas

> (I had assumed we would stop clearing the pointers after this change).
> 
> 	Sam
> 
> which prevents us from initializing these pointers
>> early after allocation.
>>
>> The change also harmonizes behavior among DRM clients. Additional DRM
>> clients will now handle failed hotplugging like fbdev does.
>>
>> Signed-off-by: Thomas Zimmermann <tzimmermann@suse.de>
>> Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>
>> ---
>>   drivers/gpu/drm/drm_client.c        | 5 +++++
>>   drivers/gpu/drm/drm_fbdev_generic.c | 4 ----
>>   include/drm/drm_client.h            | 8 ++++++++
>>   3 files changed, 13 insertions(+), 4 deletions(-)
>>
>> diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c
>> index 09ac191c202d..009e7b10455c 100644
>> --- a/drivers/gpu/drm/drm_client.c
>> +++ b/drivers/gpu/drm/drm_client.c
>> @@ -208,8 +208,13 @@ void drm_client_dev_hotplug(struct drm_device *dev)
>>   		if (!client->funcs || !client->funcs->hotplug)
>>   			continue;
>>   
>> +		if (client->hotplug_failed)
>> +			continue;
>> +
>>   		ret = client->funcs->hotplug(client);
>>   		drm_dbg_kms(dev, "%s: ret=%d\n", client->name, ret);
>> +		if (ret)
>> +			client->hotplug_failed = true;
>>   	}
>>   	mutex_unlock(&dev->clientlist_mutex);
>>   }
>> diff --git a/drivers/gpu/drm/drm_fbdev_generic.c b/drivers/gpu/drm/drm_fbdev_generic.c
>> index 3d455a2e3fb5..135d58b8007b 100644
>> --- a/drivers/gpu/drm/drm_fbdev_generic.c
>> +++ b/drivers/gpu/drm/drm_fbdev_generic.c
>> @@ -382,10 +382,6 @@ static int drm_fbdev_client_hotplug(struct drm_client_dev *client)
>>   	struct drm_device *dev = client->dev;
>>   	int ret;
>>   
>> -	/* Setup is not retried if it has failed */
>> -	if (!fb_helper->dev && fb_helper->funcs)
>> -		return 0;
>> -
>>   	if (dev->fb_helper)
>>   		return drm_fb_helper_hotplug_event(dev->fb_helper);
>>   
>> diff --git a/include/drm/drm_client.h b/include/drm/drm_client.h
>> index 4fc8018eddda..39482527a775 100644
>> --- a/include/drm/drm_client.h
>> +++ b/include/drm/drm_client.h
>> @@ -106,6 +106,14 @@ struct drm_client_dev {
>>   	 * @modesets: CRTC configurations
>>   	 */
>>   	struct drm_mode_set *modesets;
>> +
>> +	/**
>> +	 * @hotplug failed:
>> +	 *
>> +	 * Set by client hotplug helpers if the hotplugging failed
>> +	 * before. It is usually not tried again.
>> +	 */
>> +	bool hotplug_failed;
>>   };
>>   
>>   int drm_client_init(struct drm_device *dev, struct drm_client_dev *client,
>> -- 
>> 2.39.0
diff mbox series

Patch

diff --git a/drivers/gpu/drm/drm_client.c b/drivers/gpu/drm/drm_client.c
index 09ac191c202d..009e7b10455c 100644
--- a/drivers/gpu/drm/drm_client.c
+++ b/drivers/gpu/drm/drm_client.c
@@ -208,8 +208,13 @@  void drm_client_dev_hotplug(struct drm_device *dev)
 		if (!client->funcs || !client->funcs->hotplug)
 			continue;
 
+		if (client->hotplug_failed)
+			continue;
+
 		ret = client->funcs->hotplug(client);
 		drm_dbg_kms(dev, "%s: ret=%d\n", client->name, ret);
+		if (ret)
+			client->hotplug_failed = true;
 	}
 	mutex_unlock(&dev->clientlist_mutex);
 }
diff --git a/drivers/gpu/drm/drm_fbdev_generic.c b/drivers/gpu/drm/drm_fbdev_generic.c
index 3d455a2e3fb5..135d58b8007b 100644
--- a/drivers/gpu/drm/drm_fbdev_generic.c
+++ b/drivers/gpu/drm/drm_fbdev_generic.c
@@ -382,10 +382,6 @@  static int drm_fbdev_client_hotplug(struct drm_client_dev *client)
 	struct drm_device *dev = client->dev;
 	int ret;
 
-	/* Setup is not retried if it has failed */
-	if (!fb_helper->dev && fb_helper->funcs)
-		return 0;
-
 	if (dev->fb_helper)
 		return drm_fb_helper_hotplug_event(dev->fb_helper);
 
diff --git a/include/drm/drm_client.h b/include/drm/drm_client.h
index 4fc8018eddda..39482527a775 100644
--- a/include/drm/drm_client.h
+++ b/include/drm/drm_client.h
@@ -106,6 +106,14 @@  struct drm_client_dev {
 	 * @modesets: CRTC configurations
 	 */
 	struct drm_mode_set *modesets;
+
+	/**
+	 * @hotplug failed:
+	 *
+	 * Set by client hotplug helpers if the hotplugging failed
+	 * before. It is usually not tried again.
+	 */
+	bool hotplug_failed;
 };
 
 int drm_client_init(struct drm_device *dev, struct drm_client_dev *client,