[PATCH 6.6 059/158] drm/i915/mst: Limit MST+DSC to TGL+

Greg Kroah-Hartman
2024-04-23T21:43:16Z

From: Ville Syrjälä <ville.syrjala@linux.intel.com>

[ Upstream commit 51bc63392e96ca45d7be98bc43c180b174ffca09 ]

The MST code currently assumes that glk+ already supports MST+DSC,
which is incorrect. We need to check for TGL+ actually. ICL does
support SST+DSC, but supposedly it can't do MST+FEC which will
also rule out MST+DSC.

Note that a straight TGL+ check doesn't work here because DSC
support can get fused out, so we do need to also check 'has_dsc'.

Cc: stable@vger.kernel.org
Fixes: d51f25eb479a ("drm/i915: Add DSC support to MST path")
Reviewed-by: Uma Shankar <uma.shankar@intel.com>
Signed-off-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Link: https://patchwork.freedesktop.org/patch/msgid/20240402135148.23011-6-ville.syrjala@linux.intel.com
(cherry picked from commit c9c92f286dbdf872390ef3e74dbe5f0641e46f55)
Signed-off-by: Rodrigo Vivi <rodrigo.vivi@intel.com>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
drivers/gpu/drm/i915/display/intel_display_device.h | 1 +
drivers/gpu/drm/i915/display/intel_dp_mst.c | 2 +-
2 files changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/i915/display/intel_display_device.h b/drivers/gpu/drm/i915/display/intel_display_device.h
index 215e682bd8b7a..5fd07c1817766 100644
--- a/drivers/gpu/drm/i915/display/intel_display_device.h
+++ b/drivers/gpu/drm/i915/display/intel_display_device.h
@@ -46,6 +46,7 @@ struct drm_printer;
#define HAS_DPT(i915) (DISPLAY_VER(i915) >= 13)
#define HAS_DSB(i915) (DISPLAY_INFO(i915)->has_dsb)
#define HAS_DSC(__i915) (DISPLAY_RUNTIME_INFO(__i915)->has_dsc)
+#define HAS_DSC_MST(__i915) (DISPLAY_VER(__i915) >= 12 && HAS_DSC(__i915))
#define HAS_FBC(i915) (DISPLAY_RUNTIME_INFO(i915)->fbc_mask != 0)
#define HAS_FPGA_DBG_UNCLAIMED(i915) (DISPLAY_INFO(i915)->has_fpga_dbg)
#define HAS_FW_BLC(i915) (DISPLAY_VER(i915) > 2)
diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
index f104bd7f8c2a6..d2f8f20722d92 100644
--- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
@@ -964,7 +964,7 @@ intel_dp_mst_mode_valid_ctx(struct drm_connector *connector,
return 0;
}

- if (DISPLAY_VER(dev_priv) >= 10 &&
+ if (HAS_DSC_MST(dev_priv) &&
drm_dp_sink_supports_dsc(intel_dp->dsc_dpcd)) {
/*
* TBD pass the connector BPC,
--
2.43.0