From: Ville Syrjälä Date: Tue, 20 Nov 2018 13:54:49 +0000 (+0200) Subject: drm/i915: Force a LUT update in intel_initial_commit() X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=fa6af5145b4e87a30a530be0d80734a9dd40da77;p=linux.git drm/i915: Force a LUT update in intel_initial_commit() If we force a plane update to fix up our half populated plane state we'll also force on the pipe gamma for the plane (since we always enable pipe gamma currently). If the BIOS hasn't programmed a sensible LUT into the hardware this will cause the image to become corrupted. Typical symptoms are a purple/yellow/etc. flash when the driver loads. To avoid this let's program something sensible into the LUT when we do the plane update. In the future I plan to add proper plane gamma enable readout so this is just a temporary measure. Cc: Hans de Goede Fixes: 516a49cc1946 ("drm/i915: Fix assert_plane() warning on bootup with external display") Signed-off-by: Ville Syrjälä Link: https://patchwork.freedesktop.org/patch/msgid/20181120135450.3634-1-ville.syrjala@linux.intel.com Tested-by: Hans de Goede Reviewed-by: Rodrigo Vivi --- diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 132e978227fbe..60c1e54285c1e 100644 --- a/drivers/gpu/drm/i915/intel_display.c +++ b/drivers/gpu/drm/i915/intel_display.c @@ -15011,6 +15011,14 @@ retry: ret = drm_atomic_add_affected_planes(state, crtc); if (ret) goto out; + + /* + * FIXME hack to force a LUT update to avoid the + * plane update forcing the pipe gamma on without + * having a proper LUT loaded. Remove once we + * have readout for pipe gamma enable. + */ + crtc_state->color_mgmt_changed = true; } }