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Commit 8747c3b2 authored by Yujun Zhang's avatar Yujun Zhang
Browse files

disp: msm: avoid deadlock by prepending connection_mutex 



Commit caused by dpms on may use extra  modeset lock on
connection_mutex before msm_atomic_commit, so to avoid
deadlock, make the modeset lock within prepare_fence
callback to use before waiting for pending_crtcs_event.

Change-Id: Ifa2298cd030720cc0e7dcc0f80e63326b3e86768
Signed-off-by: default avatarYujun Zhang <yujunzhang@codeaurora.org>
parent eb12ef5c

msm/msm_atomic.c

+10 −0
Original line number Diff line number Diff line
@@ -689,6 +689,16 @@ int msm_atomic_commit(struct drm_device *dev, 
		c->plane_mask |= (1 << drm_plane_index(plane));

	}



	/* Protection for prepare_fence callback */

retry:

	ret = drm_modeset_lock(&state->dev->mode_config.connection_mutex,

		state->acquire_ctx);



	if (ret == -EDEADLK) {

		drm_modeset_backoff(state->acquire_ctx);

		goto retry;

	}



	/*

	 * Wait for pending updates on any of the same crtc's and then

	 * mark our set of crtc's as busy:

msm/sde/sde_kms.c

+1 −10
Original line number Diff line number Diff line
@@ -1267,7 +1267,7 @@ static void sde_kms_prepare_fence(struct msm_kms *kms, 
{

	struct drm_crtc *crtc;

	struct drm_crtc_state *old_crtc_state;

	int i, rc;

	int i;



	if (!kms || !old_state || !old_state->dev || !old_state->acquire_ctx) {

		SDE_ERROR("invalid argument(s)\n");
@@ -1275,15 +1275,6 @@ static void sde_kms_prepare_fence(struct msm_kms *kms, 
	}



	SDE_ATRACE_BEGIN("sde_kms_prepare_fence");

retry:

	/* attempt to acquire ww mutex for connection */

	rc = drm_modeset_lock(&old_state->dev->mode_config.connection_mutex,

			       old_state->acquire_ctx);



	if (rc == -EDEADLK) {

		drm_modeset_backoff(old_state->acquire_ctx);

		goto retry;

	}



	/* old_state actually contains updated crtc pointers */

	for_each_old_crtc_in_state(old_state, crtc, old_crtc_state, i) {