msm: mdss: Add lock to avoid release of active session in rotator

Add mutex lock to protect an active rotator session from being closed.
Without the lock, this can happen if a rotator closing IOCTL is
called from a separate thread.

CRs-Fixed: 2006159
Change-Id: I927a0c626bdae5ef149e12979ec4befdbac1b7f7
Signed-off-by: Benjamin Chan <bkchan@codeaurora.org>

1 files changed, 3 insertions, 0 deletions

diff --git a/drivers/video/fbdev/msm/mdss_rotator.c b/drivers/video/fbdev/msm/mdss_rotator.c
index 0307d570ff64..fdd1c0153ce0 100644
--- a/drivers/video/fbdev/msm/mdss_rotator.c
+++ b/drivers/video/fbdev/msm/mdss_rotator.c
@@ -2065,10 +2065,12 @@ static int mdss_rotator_config_session(struct mdss_rot_mgr *mgr,
 		return ret;
 	}
 
+	mutex_lock(&mgr->lock);
 	perf = mdss_rotator_find_session(private, config.session_id);
 	if (!perf) {
 		pr_err("No session with id=%u could be found\n",
 			config.session_id);
+		mutex_unlock(&mgr->lock);
 		return -EINVAL;
 	}
 
@@ -2091,6 +2093,7 @@ static int mdss_rotator_config_session(struct mdss_rot_mgr *mgr,
 		config.output.format);
 done:
 	ATRACE_END(__func__);
+	mutex_unlock(&mgr->lock);
 	return ret;
 }