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Aditya Garg
60 lines
2.5 KiB
Diff
60 lines
2.5 KiB
Diff
From b6740001d1adbfe84768b859bee038ceeccdc50c Mon Sep 17 00:00:00 2001
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From: Aun-Ali Zaidi <admin@kodeit.net>
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Date: Wed, 12 Jan 2022 22:38:15 +1100
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Subject: [PATCH] drm/amd/display: Force link_rate as LINK_RATE_RBR2 for 2018 15" Apple Retina panels
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The eDP link rate reported by the DP_MAX_LINK_RATE dpcd register (0xa) is
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contradictory to the highest rate supported reported by
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EDID (0xc = LINK_RATE_RBR2). The effects of this compounded with commit
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'4a8ca46bae8a ("drm/amd/display: Default max bpc to 16 for eDP")' results
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in no display modes being found and a dark panel.
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For now, simply force the maximum supported link rate for the eDP attached
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2018 15" Apple Retina panels.
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Additionally, we must also check the firmware revision since the device ID
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reported by the DPCD is identical to that of the more capable 16,1,
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incorrectly quirking it. We also use said firmware check to quirk the
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refreshed 15,1 models with Vega graphics as they use a slightly newer
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firmware version.
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Tested-by: Aun-Ali Zaidi <admin@kodeit.net>
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Signed-off-by: Aun-Ali Zaidi <admin@kodeit.net>
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Signed-off-by: Aditya Garg <gargaditya08@live.com>
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---
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.../gpu/drm/amd/display/dc/core/dc_link_dp.c | 19 +++++++++++++++++++
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1 file changed, 19 insertions(+)
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diff --git a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
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index 05e216524..17939ad17 100644
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--- a/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
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+++ b/drivers/gpu/drm/amd/display/dc/core/dc_link_dp.c
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@@ -5597,6 +5597,25 @@ static bool retrieve_link_cap(struct dc_link *link)
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dp_hw_fw_revision.ieee_fw_rev,
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sizeof(dp_hw_fw_revision.ieee_fw_rev));
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+ /* Quirk for Apple MBP 2018 15" Retina panels: wrong DP_MAX_LINK_RATE */
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+ {
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+ uint8_t str_mbp_2018[] = { 101, 68, 21, 103, 98, 97 };
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+ uint8_t fwrev_mbp_2018[] = { 7, 4 };
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+ uint8_t fwrev_mbp_2018_vega[] = { 8, 4 };
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+
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+ // We also check for the firmware revision as 16,1 models have an
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+ // identical device id and are incorrectly quirked otherwise.
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+ if ((link->dpcd_caps.sink_dev_id == 0x0010fa) &&
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+ !memcmp(link->dpcd_caps.sink_dev_id_str, str_mbp_2018,
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+ sizeof(str_mbp_2018)) &&
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+ (!memcmp(link->dpcd_caps.sink_fw_revision, fwrev_mbp_2018,
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+ sizeof(fwrev_mbp_2018)) ||
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+ !memcmp(link->dpcd_caps.sink_fw_revision, fwrev_mbp_2018_vega,
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+ sizeof(fwrev_mbp_2018_vega)))) {
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+ link->reported_link_cap.link_rate = LINK_RATE_RBR2;
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+ }
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+ }
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+
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memset(&link->dpcd_caps.dsc_caps, '\0',
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sizeof(link->dpcd_caps.dsc_caps));
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memset(&link->dpcd_caps.fec_cap, '\0', sizeof(link->dpcd_caps.fec_cap));
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--
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2.25.1
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