6.8-stable review patch. If anyone has any objections, please let me know.
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From: Ville Syrjälä ville.syrjala@linux.intel.com
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.s... (cherry picked from commit c9c92f286dbdf872390ef3e74dbe5f0641e46f55) Signed-off-by: Rodrigo Vivi rodrigo.vivi@intel.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.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(-)
--- 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) --- 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_c 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,