diff mbox series

[1/2] drm/i915/vlv_dsi: Add DMI quirk for wrong panel modeline in BIOS on Asus TF103C

Message ID 20220221220608.12131-1-hdegoede@redhat.com (mailing list archive)
State New, archived
Headers show
Series [1/2] drm/i915/vlv_dsi: Add DMI quirk for wrong panel modeline in BIOS on Asus TF103C | expand

Commit Message

Hans de Goede Feb. 21, 2022, 10:06 p.m. UTC
Vtotal is wrong in the BIOS supplied modeline for the DSI panel on
the Asus TF103C leading to the last line of the display being shown
as the first line.

The factory installed Android has a hardcoded modeline in its kernel,
causing it to not suffer from this BIOS bug;

and the Android boot-splash which uses the EFI FB which does have this bug
has the last line all black causing the bug to not be visible.

This commit introduces a generic DMI based mechanism for doing modeline
fixups, in case we need similar fixups on other models in the future.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
---
 drivers/gpu/drm/i915/display/vlv_dsi.c | 36 ++++++++++++++++++++++++++
 1 file changed, 36 insertions(+)

Comments

Javier Martinez Canillas Feb. 22, 2022, 8:56 a.m. UTC | #1
Hello Hans,

On 2/21/22 23:06, Hans de Goede wrote:
> Vtotal is wrong in the BIOS supplied modeline for the DSI panel on
> the Asus TF103C leading to the last line of the display being shown
> as the first line.
> 
> The factory installed Android has a hardcoded modeline in its kernel,
> causing it to not suffer from this BIOS bug;
> 
> and the Android boot-splash which uses the EFI FB which does have this bug
> has the last line all black causing the bug to not be visible.
> 
> This commit introduces a generic DMI based mechanism for doing modeline
> fixups, in case we need similar fixups on other models in the future.
> 
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
>  drivers/gpu/drm/i915/display/vlv_dsi.c | 36 ++++++++++++++++++++++++++
>  1 file changed, 36 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/display/vlv_dsi.c b/drivers/gpu/drm/i915/display/vlv_dsi.c
> index 06ef822c27bd..66f5cf32bb66 100644
> --- a/drivers/gpu/drm/i915/display/vlv_dsi.c
> +++ b/drivers/gpu/drm/i915/display/vlv_dsi.c
> @@ -23,6 +23,7 @@
>   * Author: Jani Nikula <jani.nikula@intel.com>
>   */
>  
> +#include <linux/dmi.h>
>  #include <linux/slab.h>
>  
>  #include <drm/drm_atomic_helper.h>
> @@ -1831,6 +1832,33 @@ static void vlv_dphy_param_init(struct intel_dsi *intel_dsi)
>  	intel_dsi_log_params(intel_dsi);
>  }
>  
> +typedef void (*vlv_dsi_mode_fixup_func)(struct drm_connector *connector,
> +					struct drm_display_mode *fixed_mode);
> +
> +/*
> + * Vtotal is wrong on the Asus TF103C leading to the last line of the display
> + * being shown as the first line. The factory installed Android has a hardcoded
> + * modeline, causing it to not suffer from this BIOS bug.
> + */
> +static void vlv_dsi_asus_tf103c_mode_fixup(struct drm_connector *connector,
> +					   struct drm_display_mode *fixed_mode)
> +{
> +	fixed_mode->vtotal = 816;
> +	fixed_mode->crtc_vtotal = 816;
> +}
> +
> +static const struct dmi_system_id dmi_mode_fixup_table[] = {
> +	{
> +		/* Asus Transformer Pad TF103C */
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "TF103C"),
> +		},
> +		.driver_data = (void *)vlv_dsi_asus_tf103c_mode_fixup,
> +	},
> +	{ }
> +};
> +

There's nothing driver specific in this mechanism so I wonder if would
be better to add it as a DRM helper, for others drivers to use it too.

Maybe in drivers/gpu/drm/drm_modeset_helper.c or a drm_modeset_quirks.c
like we have for drivers/gpu/drm/drm_panel_orientation_quirks.c ?

The patch looks good to me, regardless where you decide to add it.

Reviewed-by: Javier Martinez Canillas <javierm@redhat.com>

Best regards,
Ville Syrjälä Feb. 22, 2022, 9:15 a.m. UTC | #2
On Mon, Feb 21, 2022 at 11:06:07PM +0100, Hans de Goede wrote:
> Vtotal is wrong in the BIOS supplied modeline for the DSI panel on

Please include both the correct and bad modelines in the commit
msg.

> the Asus TF103C leading to the last line of the display being shown
> as the first line.
> 
> The factory installed Android has a hardcoded modeline in its kernel,
> causing it to not suffer from this BIOS bug;
> 
> and the Android boot-splash which uses the EFI FB which does have this bug
> has the last line all black causing the bug to not be visible.
> 
> This commit introduces a generic DMI based mechanism for doing modeline
> fixups, in case we need similar fixups on other models in the future.
> 
> Signed-off-by: Hans de Goede <hdegoede@redhat.com>
> ---
>  drivers/gpu/drm/i915/display/vlv_dsi.c | 36 ++++++++++++++++++++++++++
>  1 file changed, 36 insertions(+)
> 
> diff --git a/drivers/gpu/drm/i915/display/vlv_dsi.c b/drivers/gpu/drm/i915/display/vlv_dsi.c
> index 06ef822c27bd..66f5cf32bb66 100644
> --- a/drivers/gpu/drm/i915/display/vlv_dsi.c
> +++ b/drivers/gpu/drm/i915/display/vlv_dsi.c
> @@ -23,6 +23,7 @@
>   * Author: Jani Nikula <jani.nikula@intel.com>
>   */
>  
> +#include <linux/dmi.h>
>  #include <linux/slab.h>
>  
>  #include <drm/drm_atomic_helper.h>
> @@ -1831,6 +1832,33 @@ static void vlv_dphy_param_init(struct intel_dsi *intel_dsi)
>  	intel_dsi_log_params(intel_dsi);
>  }
>  
> +typedef void (*vlv_dsi_mode_fixup_func)(struct drm_connector *connector,
> +					struct drm_display_mode *fixed_mode);
> +
> +/*
> + * Vtotal is wrong on the Asus TF103C leading to the last line of the display
> + * being shown as the first line. The factory installed Android has a hardcoded
> + * modeline, causing it to not suffer from this BIOS bug.
> + */
> +static void vlv_dsi_asus_tf103c_mode_fixup(struct drm_connector *connector,
> +					   struct drm_display_mode *fixed_mode)
> +{
> +	fixed_mode->vtotal = 816;

I might prefer a full modeline here. Or maybe just vtotal-- or
something, if it's just an off by one.

> +	fixed_mode->crtc_vtotal = 816;

The crtc timings should all be 0 at this point. So this looks redundant.

> +}
> +
> +static const struct dmi_system_id dmi_mode_fixup_table[] = {
> +	{
> +		/* Asus Transformer Pad TF103C */
> +		.matches = {
> +			DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
> +			DMI_MATCH(DMI_PRODUCT_NAME, "TF103C"),
> +		},
> +		.driver_data = (void *)vlv_dsi_asus_tf103c_mode_fixup,
> +	},
> +	{ }
> +};
> +
>  void vlv_dsi_init(struct drm_i915_private *dev_priv)
>  {
>  	struct drm_device *dev = &dev_priv->drm;
> @@ -1840,6 +1868,8 @@ void vlv_dsi_init(struct drm_i915_private *dev_priv)
>  	struct intel_connector *intel_connector;
>  	struct drm_connector *connector;
>  	struct drm_display_mode *current_mode, *fixed_mode;
> +	const struct dmi_system_id *dmi_id;
> +	vlv_dsi_mode_fixup_func mode_fixup;

The function pointer can go into the if block.

>  	enum port port;
>  	enum pipe pipe;
>  
> @@ -1968,6 +1998,12 @@ void vlv_dsi_init(struct drm_i915_private *dev_priv)
>  		goto err_cleanup_connector;
>  	}
>  
> +	dmi_id = dmi_first_match(dmi_mode_fixup_table);
> +	if (dmi_id) {
> +		mode_fixup = (vlv_dsi_mode_fixup_func)dmi_id->driver_data;
> +		mode_fixup(connector, fixed_mode);
> +	}
> +
>  	intel_panel_init(&intel_connector->panel, fixed_mode, NULL);
>  	intel_backlight_setup(intel_connector, INVALID_PIPE);
>  
> -- 
> 2.35.1
diff mbox series

Patch

diff --git a/drivers/gpu/drm/i915/display/vlv_dsi.c b/drivers/gpu/drm/i915/display/vlv_dsi.c
index 06ef822c27bd..66f5cf32bb66 100644
--- a/drivers/gpu/drm/i915/display/vlv_dsi.c
+++ b/drivers/gpu/drm/i915/display/vlv_dsi.c
@@ -23,6 +23,7 @@ 
  * Author: Jani Nikula <jani.nikula@intel.com>
  */
 
+#include <linux/dmi.h>
 #include <linux/slab.h>
 
 #include <drm/drm_atomic_helper.h>
@@ -1831,6 +1832,33 @@  static void vlv_dphy_param_init(struct intel_dsi *intel_dsi)
 	intel_dsi_log_params(intel_dsi);
 }
 
+typedef void (*vlv_dsi_mode_fixup_func)(struct drm_connector *connector,
+					struct drm_display_mode *fixed_mode);
+
+/*
+ * Vtotal is wrong on the Asus TF103C leading to the last line of the display
+ * being shown as the first line. The factory installed Android has a hardcoded
+ * modeline, causing it to not suffer from this BIOS bug.
+ */
+static void vlv_dsi_asus_tf103c_mode_fixup(struct drm_connector *connector,
+					   struct drm_display_mode *fixed_mode)
+{
+	fixed_mode->vtotal = 816;
+	fixed_mode->crtc_vtotal = 816;
+}
+
+static const struct dmi_system_id dmi_mode_fixup_table[] = {
+	{
+		/* Asus Transformer Pad TF103C */
+		.matches = {
+			DMI_MATCH(DMI_SYS_VENDOR, "ASUSTeK COMPUTER INC."),
+			DMI_MATCH(DMI_PRODUCT_NAME, "TF103C"),
+		},
+		.driver_data = (void *)vlv_dsi_asus_tf103c_mode_fixup,
+	},
+	{ }
+};
+
 void vlv_dsi_init(struct drm_i915_private *dev_priv)
 {
 	struct drm_device *dev = &dev_priv->drm;
@@ -1840,6 +1868,8 @@  void vlv_dsi_init(struct drm_i915_private *dev_priv)
 	struct intel_connector *intel_connector;
 	struct drm_connector *connector;
 	struct drm_display_mode *current_mode, *fixed_mode;
+	const struct dmi_system_id *dmi_id;
+	vlv_dsi_mode_fixup_func mode_fixup;
 	enum port port;
 	enum pipe pipe;
 
@@ -1968,6 +1998,12 @@  void vlv_dsi_init(struct drm_i915_private *dev_priv)
 		goto err_cleanup_connector;
 	}
 
+	dmi_id = dmi_first_match(dmi_mode_fixup_table);
+	if (dmi_id) {
+		mode_fixup = (vlv_dsi_mode_fixup_func)dmi_id->driver_data;
+		mode_fixup(connector, fixed_mode);
+	}
+
 	intel_panel_init(&intel_connector->panel, fixed_mode, NULL);
 	intel_backlight_setup(intel_connector, INVALID_PIPE);