[PATCH v2] drm: Fix crtc color management when doing suspend/resume

[Alexandru-Cosmin Gheorghe]

On Tue, Aug 28, 2018 at 06:46:07PM +0300, Ville Syrjälä wrote:
> On Tue, Aug 28, 2018 at 04:33:20PM +0100, Alexandru Gheorghe wrote:
> > When doing suspend/resume drivers usually use the
> > drm_atomic_helper_suspend/drm_atomic_helper_resume pair for saving the
> > state and then re-comitting it.
> > 
> > The problem is that drm_crtc_state has a bool field called
> > color_mgmt_changed, which mali-dp and other drivers uses it to detect
> > if coefficients need to be reprogrammed, but that never happens
> > because the saved state has color_mgmt_changed set to 0.
> > 
> > Fix that by setting color_mgmt_changed to true in
> > drm_atomic_helper_check_modeset when at least one of gamma_lut,
> > degamma_lut, ctm is different between the new and the old crtc state.
> > 
> > Also, this makes unnecessary the setting of color_mgmt_changed in
> > places where gamma_lut/degamma_lut/ctm are set in the new crtc_state.
> 
> Do all current drivers actually call drm_atomic_helper_check_modeset()
> for every commit?

Yes, all drivers that use color_mgmt_changed either call directly
drm_atomic_helper_check_modeset or they use drm_atomic_helper_check
which calls drm_atomic_helper_check_modeset.

> 
> > 
> > Changes since v2:
> >   - Instead of setting color_mgmt_changed in commit_duplicated_set
> >     just set it in check_modeset and clean up other place where it was
> >     set, suggested by Maarten Lankhorst.
> > 
> > Signed-off-by: Alexandru Gheorghe <alexandru-cosmin.gheorghe at arm.com>
> > ---
> >  drivers/gpu/drm/drm_atomic.c        | 12 +++---------
> >  drivers/gpu/drm/drm_atomic_helper.c |  8 +++++++-
> >  drivers/gpu/drm/drm_fb_helper.c     |  1 -
> >  3 files changed, 10 insertions(+), 11 deletions(-)
> > 
> > diff --git a/drivers/gpu/drm/drm_atomic.c b/drivers/gpu/drm/drm_atomic.c
> > index d0478abc01bd..9bcada3c299e 100644
> > --- a/drivers/gpu/drm/drm_atomic.c
> > +++ b/drivers/gpu/drm/drm_atomic.c
> > @@ -554,29 +554,23 @@ int drm_atomic_crtc_set_property(struct drm_crtc *crtc,
> >  		drm_property_blob_put(mode);
> >  		return ret;
> >  	} else if (property == config->degamma_lut_property) {
> > -		ret = drm_atomic_replace_property_blob_from_id(dev,
> > +		return drm_atomic_replace_property_blob_from_id(dev,
> >  					&state->degamma_lut,
> >  					val,
> >  					-1, sizeof(struct drm_color_lut),
> >  					&replaced);
> > -		state->color_mgmt_changed |= replaced;
> > -		return ret;
> >  	} else if (property == config->ctm_property) {
> > -		ret = drm_atomic_replace_property_blob_from_id(dev,
> > +		return drm_atomic_replace_property_blob_from_id(dev,
> >  					&state->ctm,
> >  					val,
> >  					sizeof(struct drm_color_ctm), -1,
> >  					&replaced);
> > -		state->color_mgmt_changed |= replaced;
> > -		return ret;
> >  	} else if (property == config->gamma_lut_property) {
> > -		ret = drm_atomic_replace_property_blob_from_id(dev,
> > +		return drm_atomic_replace_property_blob_from_id(dev,
> >  					&state->gamma_lut,
> >  					val,
> >  					-1, sizeof(struct drm_color_lut),
> >  					&replaced);
> > -		state->color_mgmt_changed |= replaced;
> > -		return ret;
> >  	} else if (property == config->prop_out_fence_ptr) {
> >  		s32 __user *fence_ptr = u64_to_user_ptr(val);
> >  
> > diff --git a/drivers/gpu/drm/drm_atomic_helper.c b/drivers/gpu/drm/drm_atomic_helper.c
> > index 2c23a48482da..fe22e1ad468a 100644
> > --- a/drivers/gpu/drm/drm_atomic_helper.c
> > +++ b/drivers/gpu/drm/drm_atomic_helper.c
> > @@ -611,6 +611,13 @@ drm_atomic_helper_check_modeset(struct drm_device *dev,
> >  
> >  			return -EINVAL;
> >  		}
> > +		if (new_crtc_state->degamma_lut != old_crtc_state->degamma_lut ||
> > +		    new_crtc_state->ctm != old_crtc_state->ctm ||
> > +		    new_crtc_state->gamma_lut != old_crtc_state->gamma_lut) {
> > +			DRM_DEBUG_ATOMIC("[CRTC:%d:%s] color management changed\n",
> > +					 crtc->base.id, crtc->name);
> > +			new_crtc_state->color_mgmt_changed = true;
> > +		}
> >  	}
> >  
> >  	ret = handle_conflicting_encoders(state, false);
> > @@ -3947,7 +3954,6 @@ int drm_atomic_helper_legacy_gamma_set(struct drm_crtc *crtc,
> >  	replaced  = drm_property_replace_blob(&crtc_state->degamma_lut, NULL);
> >  	replaced |= drm_property_replace_blob(&crtc_state->ctm, NULL);
> >  	replaced |= drm_property_replace_blob(&crtc_state->gamma_lut, blob);
> > -	crtc_state->color_mgmt_changed |= replaced;
> >  
> >  	ret = drm_atomic_commit(state);
> >  
> > diff --git a/drivers/gpu/drm/drm_fb_helper.c b/drivers/gpu/drm/drm_fb_helper.c
> > index 4b0dd20bccb8..8541e95a5410 100644
> > --- a/drivers/gpu/drm/drm_fb_helper.c
> > +++ b/drivers/gpu/drm/drm_fb_helper.c
> > @@ -1442,7 +1442,6 @@ static int setcmap_atomic(struct fb_cmap *cmap, struct fb_info *info)
> >  		replaced |= drm_property_replace_blob(&crtc_state->ctm, NULL);
> >  		replaced |= drm_property_replace_blob(&crtc_state->gamma_lut,
> >  						      gamma_lut);
> > -		crtc_state->color_mgmt_changed |= replaced;
> >  	}
> >  
> >  	ret = drm_atomic_commit(state);
> > -- 
> > 2.18.0
> > 
> > _______________________________________________
> > dri-devel mailing list
> > dri-devel at lists.freedesktop.org
> > https://lists.freedesktop.org/mailman/listinfo/dri-devel
> 
> -- 
> Ville Syrjälä
> Intel

-- 
Cheers,
Alex G