On Wed, May 27, 2026 at 1:23 AM Borah, Chaitanya Kumar < [email protected]> wrote:
> Hello Sean, > > On 5/22/2026 1:09 AM, Sean Paul wrote: > > From: Sean Paul <[email protected]> > > > > Fix a typo in the loop condition in xelpd_program_plane_pre_csc_lut > > for Segment 2 degamma programming, changing 'while (i++ > 130)' to > > 'while (i++ < 130)'. Also clamp Segment 2 to the last user-provided > > LUT entry value instead of hardcoding it to 1.0 (1 << 24) to fix > > a step discontinuity. > > The commit message needs an update. > Ack. > Is there an easy way to reproduce the problem you are seeing (e.g. IGT)? > Unfortunately I don't have an IGT test, it's reproducing readily with our userspace. Sean I am wondering if we have to do the same on the pipe Gamma and Degamma. > > == > Chaitanya > > > > > Link: > https://lore.kernel.org/intel-gfx/[email protected]/ > #v1 > > Signed-off-by: Sean Paul <[email protected]> > > > > Changes in v2: > > - Split out into separate patches for pre/post csc fixes > > - Dropped loop bounds fix in favor of [1] > > > > [1]- > https://lore.kernel.org/r/[email protected] > > --- > > drivers/gpu/drm/i915/display/intel_color.c | 5 +++-- > > 1 file changed, 3 insertions(+), 2 deletions(-) > > > > diff --git a/drivers/gpu/drm/i915/display/intel_color.c > b/drivers/gpu/drm/i915/display/intel_color.c > > index 90d5dc2ef3e4..469011c83f9b 100644 > > --- a/drivers/gpu/drm/i915/display/intel_color.c > > +++ b/drivers/gpu/drm/i915/display/intel_color.c > > @@ -3953,6 +3953,7 @@ xelpd_program_plane_pre_csc_lut(struct intel_dsb > *dsb, > > enum plane_id plane = to_intel_plane(state->plane)->id; > > const struct drm_color_lut32 *pre_csc_lut = > plane_state->hw.degamma_lut->data; > > u32 i, lut_size; > > + u32 lut_val = 1 << 24; > > > > if (icl_is_hdr_plane(display, plane)) { > > lut_size = 128; > > @@ -3963,7 +3964,7 @@ xelpd_program_plane_pre_csc_lut(struct intel_dsb > *dsb, > > > > if (pre_csc_lut) { > > for (i = 0; i < lut_size; i++) { > > - u32 lut_val = > drm_color_lut32_extract(pre_csc_lut[i].green, 24); > > + lut_val = > drm_color_lut32_extract(pre_csc_lut[i].green, 24); > > > > intel_de_write_dsb(display, dsb, > > > PLANE_PRE_CSC_GAMC_DATA_ENH(pipe, plane, 0), > > @@ -3975,7 +3976,7 @@ xelpd_program_plane_pre_csc_lut(struct intel_dsb > *dsb, > > do { > > intel_de_write_dsb(display, dsb, > > > PLANE_PRE_CSC_GAMC_DATA_ENH(pipe, plane, 0), > > - (1 << 24)); > > + lut_val); > > } while (i++ > 130); > > } else { > > for (i = 0; i < lut_size; i++) { > >
