The patch below does not apply to the 6.11-stable tree. If someone wants it applied there, or to any other stable or longterm tree, then please email the backport, including the original git commit id to stable@vger.kernel.org.

To reproduce the conflict and resubmit, you may use the following commands:

git fetch https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/ linux-6.11.y git checkout FETCH_HEAD git cherry-pick -x 33eca84db6e31091cef63584158ab64704f78462 # <resolve conflicts, build, test, etc.> git commit -s git send-email --to 'stable@vger.kernel.org' --in-reply-to '2024100859-bogus-pursuable-6b33@gregkh' --subject-prefix 'PATCH 6.11.y' HEAD^..

Possible dependencies:

33eca84db6e3 ("drm/i915: Fix readout degamma_lut mismatch on ilk/snb")

thanks,

greg k-h

------------------ original commit in Linus's tree ------------------

From 33eca84db6e31091cef63584158ab64704f78462 Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= ville.syrjala@linux.intel.com Date: Wed, 10 Jul 2024 15:41:37 +0300 Subject: [PATCH] drm/i915: Fix readout degamma_lut mismatch on ilk/snb MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit

On ilk/snb the pipe may be configured to place the LUT before or after the CSC depending on various factors, but as there is only one LUT (no split mode like on IVB+) we only advertise a gamma_lut and no degamma_lut in the uapi to avoid confusing userspace.

This can cause a problem during readout if the VBIOS/GOP enabled the LUT in the pre CSC configuration. The current code blindly assigns the results of the readout to the degamma_lut, which will cause a failure during the next atomic_check() as we aren't expecting anything to be in degamma_lut since it's not visible to userspace.

Fix the problem by assigning whatever LUT we read out from the hardware into gamma_lut.

Cc: stable@vger.kernel.org Fixes: d2559299d339 ("drm/i915: Make ilk_read_luts() capable of degamma readout") Closes: https://gitlab.freedesktop.org/drm/i915/kernel/-/issues/11608 Signed-off-by: Ville Syrjälä ville.syrjala@linux.intel.com Link: https://patchwork.freedesktop.org/patch/msgid/20240710124137.16773-1-ville.s... Reviewed-by: Uma Shankar uma.shankar@intel.com

diff --git a/drivers/gpu/drm/i915/display/intel_modeset_setup.c b/drivers/gpu/drm/i915/display/intel_modeset_setup.c index 6f85f5352455..72694dde3c22 100644 --- a/drivers/gpu/drm/i915/display/intel_modeset_setup.c +++ b/drivers/gpu/drm/i915/display/intel_modeset_setup.c @@ -326,6 +326,8 @@ static void intel_modeset_update_connector_atomic_state(struct drm_i915_private

static void intel_crtc_copy_hw_to_uapi_state(struct intel_crtc_state *crtc_state) { + struct drm_i915_private *i915 = to_i915(crtc_state->uapi.crtc->dev); + if (intel_crtc_is_joiner_secondary(crtc_state)) return;

@@ -337,11 +339,30 @@ static void intel_crtc_copy_hw_to_uapi_state(struct intel_crtc_state *crtc_state crtc_state->uapi.adjusted_mode = crtc_state->hw.adjusted_mode; crtc_state->uapi.scaling_filter = crtc_state->hw.scaling_filter;

- /* assume 1:1 mapping */ - drm_property_replace_blob(&crtc_state->hw.degamma_lut, - crtc_state->pre_csc_lut); - drm_property_replace_blob(&crtc_state->hw.gamma_lut, - crtc_state->post_csc_lut); + if (DISPLAY_INFO(i915)->color.degamma_lut_size) { + /* assume 1:1 mapping */ + drm_property_replace_blob(&crtc_state->hw.degamma_lut, + crtc_state->pre_csc_lut); + drm_property_replace_blob(&crtc_state->hw.gamma_lut, + crtc_state->post_csc_lut); + } else { + /* + * ilk/snb hw may be configured for either pre_csc_lut + * or post_csc_lut, but we don't advertise degamma_lut as + * being available in the uapi since there is only one + * hardware LUT. Always assign the result of the readout + * to gamma_lut as that is the only valid source of LUTs + * in the uapi. + */ + drm_WARN_ON(&i915->drm, crtc_state->post_csc_lut && + crtc_state->pre_csc_lut); + + drm_property_replace_blob(&crtc_state->hw.degamma_lut, + NULL); + drm_property_replace_blob(&crtc_state->hw.gamma_lut, + crtc_state->post_csc_lut ?: + crtc_state->pre_csc_lut); + }

drm_property_replace_blob(&crtc_state->uapi.degamma_lut, crtc_state->hw.degamma_lut);