From fa6af5145b4e87a30a530be0d80734a9dd40da77 Mon Sep 17 00:00:00 2001 From: =?utf8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Tue, 20 Nov 2018 15:54:49 +0200 Subject: [PATCH] drm/i915: Force a LUT update in intel_initial_commit() MIME-Version: 1.0 Content-Type: text/plain; charset=utf8 Content-Transfer-Encoding: 8bit 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 --- drivers/gpu/drm/i915/intel_display.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/gpu/drm/i915/intel_display.c b/drivers/gpu/drm/i915/intel_display.c index 132e978..60c1e54 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; } } -- 2.7.4