On Thu, 08 Feb 2024, Ville Syrjala ville.syrjala@linux.intel.com wrote:

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

Limit the link rate to HBR3 or below (<=8.1Gbps) in SST mode. UHBR (10Gbps+) link rates require 128b/132b channel encoding which we have not yet hooked up into the SST/no-sideband codepaths.

Cc: stable@vger.kernel.org Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com

My bad.

I guess this is the smallest most isolated fix for stable.

Reviewed-by: Jani Nikula jani.nikula@intel.com

---

drivers/gpu/drm/i915/display/intel_dp.c | 3 +++ 1 file changed, 3 insertions(+)

diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index ab415f41924d..5045c34a16be 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -2356,6 +2356,9 @@ intel_dp_compute_config_limits(struct intel_dp *intel_dp, limits->min_rate = intel_dp_common_rate(intel_dp, 0); limits->max_rate = intel_dp_max_link_rate(intel_dp);

• /* FIXME 128b/132b SST support missing */
• limits->max_rate = min(limits->max_rate, 810000);
• limits->min_lane_count = 1; limits->max_lane_count = intel_dp_max_lane_count(intel_dp);