This is a note to let you know that I've just added the patch titled drm/i915/mst: Limit MST+DSC to TGL+ to the 6.8-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: drm-i915-mst-limit-mst-dsc-to-tgl.patch and it can be found in the queue-6.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From 51bc63392e96ca45d7be98bc43c180b174ffca09 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= <ville.syrjala@xxxxxxxxxxxxxxx> Date: Tue, 2 Apr 2024 16:51:46 +0300 Subject: drm/i915/mst: Limit MST+DSC to TGL+ MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit From: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> 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@xxxxxxxxxxxxxxx Fixes: d51f25eb479a ("drm/i915: Add DSC support to MST path") Reviewed-by: Uma Shankar <uma.shankar@xxxxxxxxx> Signed-off-by: Ville Syrjälä <ville.syrjala@xxxxxxxxxxxxxxx> Link: https://patchwork.freedesktop.org/patch/msgid/20240402135148.23011-6-ville.syrjala@xxxxxxxxxxxxxxx (cherry picked from commit c9c92f286dbdf872390ef3e74dbe5f0641e46f55) Signed-off-by: Rodrigo Vivi <rodrigo.vivi@xxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- 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, Patches currently in stable-queue which might be from ville.syrjala@xxxxxxxxxxxxxxx are queue-6.8/drm-i915-mst-reject-fec-mst-on-icl.patch queue-6.8/drm-i915-stop-doing-double-audio-enable-disable-on-s.patch queue-6.8/drm-i915-mst-limit-mst-dsc-to-tgl.patch