From: Lyude Paul Date: Thu, 12 Dec 2019 09:07:43 +0000 (+0800) Subject: UBUNTU: SAUCE: drm/i915: Force DPCD backlight mode on X1 Extreme 2nd Gen 4K AMOLED... X-Git-Tag: Ubuntu-5.4-5.4.0-11.14~1001 X-Git-Url: https://git.proxmox.com/?a=commitdiff_plain;h=163215682f9be577adefacdc97ed3cd45af849e2;p=mirror_ubuntu-focal-kernel.git UBUNTU: SAUCE: drm/i915: Force DPCD backlight mode on X1 Extreme 2nd Gen 4K AMOLED panel BugLink: https://bugs.launchpad.net/bugs/1856134 Annoyingly, the VBT on the ThinkPad X1 Extreme 2nd Gen indicates that the system uses plain PWM based backlight controls, when in reality the only backlight controls that work are the standard VESA eDP DPCD backlight controls. Honestly, this makes me wonder how many other systems have these issues or lie about this in their VBT. Not sure we have any good way of finding out until panels like this become more common place in the laptop market. For now, just add a DRM DP quirk to indicate that this panel is telling the truth and is being a good LCD. Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=112376 Signed-off-by: Lyude Paul Acked-by: Jani Nikula (backported from https://patchwork.freedesktop.org/patch/342166/?series=69914&rev=4) Signed-off-by: AceLan Kao Signed-off-by: Seth Forshee --- diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index ffc68d305afe..f1f14f4144e3 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -1260,6 +1260,10 @@ static const struct dpcd_quirk dpcd_quirk_list[] = { { OUI(0x00, 0x10, 0xfa), DEVICE_ID_ANY, false, BIT(DP_DPCD_QUIRK_NO_PSR) }, /* CH7511 seems to leave SINK_COUNT zeroed */ { OUI(0x00, 0x00, 0x00), DEVICE_ID('C', 'H', '7', '5', '1', '1'), false, BIT(DP_DPCD_QUIRK_NO_SINK_COUNT) }, + /* Optional 4K AMOLED panel in the ThinkPad X1 Extreme 2nd Generation + * only supports DPCD backlight controls, despite advertising otherwise + */ + { OUI(0xba, 0x41, 0x59), DEVICE_ID_ANY, false, BIT(DP_DPCD_QUIRK_FORCE_DPCD_BACKLIGHT) }, }; #undef OUI diff --git a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c index 87b59db9ffe3..3d61260b08ad 100644 --- a/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c +++ b/drivers/gpu/drm/i915/display/intel_dp_aux_backlight.c @@ -325,11 +325,17 @@ intel_dp_aux_display_control_capable(struct intel_connector *connector) int intel_dp_aux_init_backlight_funcs(struct intel_connector *intel_connector) { struct intel_panel *panel = &intel_connector->panel; - struct drm_i915_private *dev_priv = to_i915(intel_connector->base.dev); + struct intel_dp *intel_dp = + enc_to_intel_dp(&intel_connector->encoder->base); + struct drm_i915_private *dev_priv = + to_i915(intel_connector->base.dev); if (i915_modparams.enable_dpcd_backlight == 0 || (i915_modparams.enable_dpcd_backlight == -1 && - dev_priv->vbt.backlight.type != INTEL_BACKLIGHT_VESA_EDP_AUX_INTERFACE)) + dev_priv->vbt.backlight.type != + INTEL_BACKLIGHT_VESA_EDP_AUX_INTERFACE && + !drm_dp_has_quirk(&intel_dp->desc, + DP_DPCD_QUIRK_FORCE_DPCD_BACKLIGHT))) return -ENODEV; if (!intel_dp_aux_display_control_capable(intel_connector)) diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h index 8364502f92cf..cd22d632fd74 100644 --- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -1434,6 +1434,14 @@ enum drm_dp_quirk { * The driver should ignore SINK_COUNT during detection. */ DP_DPCD_QUIRK_NO_SINK_COUNT, + /** + * @DP_DPCD_QUIRK_FORCE_DPCD_BACKLIGHT: + * + * The device is telling the truth when it says that it uses DPCD + * backlight controls, even if the system's firmware disagrees. + * The driver should honor the DPCD backlight capabilities advertised. + */ + DP_DPCD_QUIRK_FORCE_DPCD_BACKLIGHT, }; /**