Use recommended values as per wa_14021694213 to compare with the calculated value and choose minimum of them.
v2: corrected checkpatch warning and retain the restriction for min_hblank (Jani) v3: use calculated value to compare with recomended value and choose minimum of them (Imre) Bspec: 74379 Signed-off-by: Arun R Murthy <arun.r.mur...@intel.com> --- Changes in v3: - EDITME: describe what is new in this series revision. - EDITME: use bulletpoints and terse descriptions. - Link to v2: https://lore.kernel.org/r/20250624-min_hblank-v2-1-9110a9342...@intel.com Changes in v2: - EDITME: describe what is new in this series revision. - EDITME: use bulletpoints and terse descriptions. - Link to v1: https://lore.kernel.org/r/20250624-min_hblank-v1-1-5c100e4a8...@intel.com --- drivers/gpu/drm/i915/display/intel_dp.c | 17 ++++++++++++++++- 1 file changed, 16 insertions(+), 1 deletion(-) diff --git a/drivers/gpu/drm/i915/display/intel_dp.c b/drivers/gpu/drm/i915/display/intel_dp.c index f48912f308df7fd26c9d089e8f1bd096bfc8df95..c55315fb74734fded40695bae40dd19f71a9786f 100644 --- a/drivers/gpu/drm/i915/display/intel_dp.c +++ b/drivers/gpu/drm/i915/display/intel_dp.c @@ -3175,7 +3175,22 @@ int intel_dp_compute_min_hblank(struct intel_crtc_state *crtc_state, */ min_hblank = min_hblank - 2; - min_hblank = min(10, min_hblank); + /* + * min_hblank formula is undergoing a change, to avoid underrun use the + * recomended value in spec to compare with the calculated one and use the + * minimum value + */ + if (intel_dp_is_uhbr(crtc_state)) { + if (crtc_state->dsc.compression_enable && + crtc_state->output_format == INTEL_OUTPUT_FORMAT_YCBCR420 && + crtc_state->pipe_bpp == 18) + min_hblank = min(2, min_hblank); + else + min_hblank = min(3, min_hblank); + } else { + min_hblank = min(10, min_hblank); + } + crtc_state->min_hblank = min_hblank; return 0; --- base-commit: da56936fad6f5e1d5f0cef8b50277bfb071eefe7 change-id: 20250624-min_hblank-8af8d2626ff8 Best regards, -- Arun R Murthy <arun.r.mur...@intel.com>
