drm/i915/mst: Limit MST+DSC to TGL+

commit 51bc63392e96ca45d7be98bc43c180b174ffca09 upstream.

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: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

diff --git a/drivers/gpu/drm/i915/display/intel_display_device.h b/drivers/gpu/drm/i915/display/intel_display_device.h
index fe42688137863ca8dc95057aa3fffe5ada026211..9b1bce2624b9ea1a8e45bcc5b76e4621703d073e 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_display_device.h
+++ b/drivers/gpu/drm/i915/display/intel_display_device.h
@@ -47,6 +47,7 @@ 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) >= 3)

diff --git a/drivers/gpu/drm/i915/display/intel_dp_mst.c b/drivers/gpu/drm/i915/display/intel_dp_mst.c
index a01a59f57ae5525acb65e2725b3b37a9e31a065c..2151e916ccfa41863805e6cd7465c72d5d5d0169 100644 (file)
--- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
@@ -1338,7 +1338,7 @@ 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_connector->dp.dsc_dpcd)) {
                /*
                 * TBD pass the connector BPC,