6.11-stable review patch. If anyone has any objections, please let me know.
------------------
From: Imre Deak <imre.deak@xxxxxxxxx>
commit 2f54e71359eb2abc0bdf6619cd356e5e350ff27b upstream.
If an MST branch device doesn't support DSC for a given mode, but the
MST link has enough BW for the mode, assume that the branch device does
support the mode using an uncompressed stream.
Fixes: 55eaef164174 ("drm/i915/dp_mst: Handle the Synaptics HBlank expansion quirk")
Cc: stable@xxxxxxxxxxxxxxx # v6.8+
Reviewed-by: Suraj Kandpal <suraj.kandpal@xxxxxxxxx>
Signed-off-by: Imre Deak <imre.deak@xxxxxxxxx>
Link: https://patchwork.freedesktop.org/patch/msgid/20241009110135.1216498-2-imre.deak@xxxxxxxxx
(cherry picked from commit 4e75c3e208a06ad6fd9b3517fb77337460d7c2b0)
Signed-off-by: Joonas Lahtinen <joonas.lahtinen@xxxxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
drivers/gpu/drm/i915/display/intel_dp_mst.c | 3 +++
1 file changed, 3 insertions(+)
--- a/drivers/gpu/drm/i915/display/intel_dp_mst.c
+++ b/drivers/gpu/drm/i915/display/intel_dp_mst.c
@@ -465,6 +465,9 @@ hblank_expansion_quirk_needs_dsc(const s
if (mode_hblank_period_ns(adjusted_mode) > hblank_limit)
return false;
+ if (!intel_dp_mst_dsc_get_slice_count(connector, crtc_state))
+ return false;
+
return true;
}
