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Commit afd65eb4 authored by Matt Roper's avatar Matt Roper Committed by Daniel Vetter
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drm/i915: Ensure plane->state->fb stays in sync with plane->fb 

plane->state->fb and plane->fb should always reference the same FB so
that atomic and legacy codepaths have the same view of display state.
In commit

        commit db068420560511de80ac59222644f2bdf278c3d5
        Author: Matt Roper <matthew.d.roper@intel.com>
        Date:   Fri Jan 30 16:22:36 2015 -0800

            drm/i915: Keep plane->state updated on pageflip

we already fixed one case where these two pointers could get out of
sync.  However it turns out there are a few other places (mainly dealing
with initial FB setup at boot) that directly set plane->fb and neglect
to update plane->state->fb.  If we never do a successful update through
the atomic pipeline, the RmFB cleanup code will look at the
plane->state->fb pointer, which has never actually been set to a
legitimate value, and try to clean it up, leading to BUG's.

Add a quick helper function to synchronize plane->state->fb with
plane->fb (and update reference counts accordingly) and call it
everywhere the driver tries to manually set plane->fb outside of the
atomic pipeline.

Bugzilla: https://bugs.freedesktop.org/show_bug.cgi?id=88909


Signed-off-by: default avatarMatt Roper <matthew.d.roper@intel.com>
Signed-off-by: default avatarDaniel Vetter <daniel.vetter@ffwll.ch>
parent 62659920

drivers/gpu/drm/i915/intel_display.c

+22 −7
Original line number Diff line number Diff line
@@ -2410,6 +2410,20 @@ intel_alloc_plane_obj(struct intel_crtc *crtc, 
	return false;

}



/* Update plane->state->fb to match plane->fb after driver-internal updates */

static void

update_state_fb(struct drm_plane *plane)

{

	if (plane->fb == plane->state->fb)

		return;



	if (plane->state->fb)

		drm_framebuffer_unreference(plane->state->fb);

	plane->state->fb = plane->fb;

	if (plane->state->fb)

		drm_framebuffer_reference(plane->state->fb);

}



static void

intel_find_plane_obj(struct intel_crtc *intel_crtc,

		     struct intel_initial_plane_config *plane_config)
@@ -2456,6 +2470,8 @@ intel_find_plane_obj(struct intel_crtc *intel_crtc, 
			break;

		}

	}



	update_state_fb(intel_crtc->base.primary);

}



static void i9xx_update_primary_plane(struct drm_crtc *crtc,
@@ -6635,6 +6651,7 @@ i9xx_get_initial_plane_config(struct intel_crtc *crtc, 
		      plane_config->size);



	crtc->base.primary->fb = fb;

	update_state_fb(crtc->base.primary);

}



static void chv_crtc_clock_get(struct intel_crtc *crtc,
@@ -7672,6 +7689,7 @@ skylake_get_initial_plane_config(struct intel_crtc *crtc, 
		      plane_config->size);



	crtc->base.primary->fb = fb;

	update_state_fb(crtc->base.primary);

	return;



error:
@@ -7763,6 +7781,7 @@ ironlake_get_initial_plane_config(struct intel_crtc *crtc, 
		      plane_config->size);



	crtc->base.primary->fb = fb;

	update_state_fb(crtc->base.primary);

}



static bool ironlake_get_pipe_config(struct intel_crtc *crtc,
@@ -9800,13 +9819,7 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc, 
	drm_gem_object_reference(&obj->base);



	crtc->primary->fb = fb;



	/* Keep state structure in sync */

	if (crtc->primary->state->fb)

		drm_framebuffer_unreference(crtc->primary->state->fb);

	crtc->primary->state->fb = fb;

	if (crtc->primary->state->fb)

		drm_framebuffer_reference(crtc->primary->state->fb);

	update_state_fb(crtc->primary);



	work->pending_flip_obj = obj;
@@ -9875,6 +9888,7 @@ static int intel_crtc_page_flip(struct drm_crtc *crtc, 
cleanup_pending:

	atomic_dec(&intel_crtc->unpin_work_count);

	crtc->primary->fb = old_fb;

	update_state_fb(crtc->primary);

	drm_framebuffer_unreference(work->old_fb);

	drm_gem_object_unreference(&obj->base);

	mutex_unlock(&dev->struct_mutex);
@@ -13709,6 +13723,7 @@ void intel_modeset_gem_init(struct drm_device *dev) 
				  to_intel_crtc(c)->pipe);

			drm_framebuffer_unreference(c->primary->fb);

			c->primary->fb = NULL;

			update_state_fb(c->primary);

		}

	}

	mutex_unlock(&dev->struct_mutex);