From 639e0db2d70fb84833d96e782cc4a01825e03b13 Mon Sep 17 00:00:00 2001 From: Mario Kleiner Date: Mon, 16 Mar 2020 05:23:40 +0100 Subject: [PATCH] drm/i915/dp: Add dpcd link_rate quirk for Apple 15" MBP 2017 (v3) This fixes a problem found on the MacBookPro 2017 Retina panel. The panel reports 10 bpc color depth in its EDID, and the firmware chooses link settings at boot which support enough bandwidth for 10 bpc (324000 kbit/sec = multiplier 0xc), but the DP_MAX_LINK_RATE dpcd register only reports 2.7 Gbps (multiplier value 0xa) as possible, in direct contradiction of what the firmware successfully set up. This restricts the panel to 8 bpc, not providing the full color depth of the panel. This patch adds a quirk specific to the MBP 2017 15" Retina panel to add the additiional 324000 kbps link rate during edp setup. Link to previous discussion of a different attempted fix with Ville and Jani: https://patchwork.kernel.org/patch/11325935/ v2: Follow Jani's proposal of defining quirk_rates[] instead of just appending 324000. This for better clarity. v3: Rebased onto current drm-tip, as of 16-March-2020. Adapt to new edid_quirks parameter of drm_dp_has_quirk(). Signed-off-by: Mario Kleiner Tested-by: Mario Kleiner Cc: Jani Nikula Signed-off-by: Jani Nikula Link: https://patchwork.freedesktop.org/patch/msgid/20200316042340.4783-1-mario.kleiner.de@gmail.com --- drivers/gpu/drm/drm_dp_helper.c | 2 ++ drivers/gpu/drm/i915/display/intel_dp.c | 11 +++++++++++ include/drm/drm_dp_helper.h | 7 +++++++ 3 files changed, 20 insertions(+) diff --git a/drivers/gpu/drm/drm_dp_helper.c b/drivers/gpu/drm/drm_dp_helper.c index 620d78ff2706..688c475d52b5 100644 --- a/drivers/gpu/drm/drm_dp_helper.c +++ b/drivers/gpu/drm/drm_dp_helper.c @@ -1179,6 +1179,8 @@ static const struct dpcd_quirk dpcd_quirk_list[] = { { OUI(0x00, 0x00, 0x00), DEVICE_ID('C', 'H', '7', '5', '1', '1'), false, BIT(DP_DPCD_QUIRK_NO_SINK_COUNT) }, /* Synaptics DP1.4 MST hubs can support DSC without virtual DPCD */ { OUI(0x90, 0xCC, 0x24), DEVICE_ID_ANY, true, BIT(DP_DPCD_QUIRK_DSC_WITHOUT_VIRTUAL_DPCD) }, + /* Apple MacBookPro 2017 15 inch eDP Retina panel reports too low DP_MAX_LINK_RATE */ + { OUI(0x00, 0x10, 0xfa), DEVICE_ID(101, 68, 21, 101, 98, 97), false, BIT(DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS) }, }; #undef OUI diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index 0a417cd2af2b..ef2e06e292d5 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -164,6 +164,17 @@ static void intel_dp_set_sink_rates(struct intel_dp *intel_dp) }; int i, max_rate; + if (drm_dp_has_quirk(&intel_dp->desc, 0, + DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS)) { + /* Needed, e.g., for Apple MBP 2017, 15 inch eDP Retina panel */ + static const int quirk_rates[] = { 162000, 270000, 324000 }; + + memcpy(intel_dp->sink_rates, quirk_rates, sizeof(quirk_rates)); + intel_dp->num_sink_rates = ARRAY_SIZE(quirk_rates); + + return; + } + max_rate = drm_dp_bw_code_to_link_rate(intel_dp->dpcd[DP_MAX_LINK_RATE]); for (i = 0; i < ARRAY_SIZE(dp_rates); i++) { diff --git a/include/drm/drm_dp_helper.h b/include/drm/drm_dp_helper.h index c5580e988826..4cc4133853c8 100644 --- a/include/drm/drm_dp_helper.h +++ b/include/drm/drm_dp_helper.h @@ -1545,6 +1545,13 @@ enum drm_dp_quirk { * capabilities advertised. */ DP_QUIRK_FORCE_DPCD_BACKLIGHT, + /** + * @DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS: + * + * The device supports a link rate of 3.24 Gbps (multiplier 0xc) despite + * the DP_MAX_LINK_RATE register reporting a lower max multiplier. + */ + DP_DPCD_QUIRK_CAN_DO_MAX_LINK_RATE_3_24_GBPS, }; /** -- 2.30.2