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,