From: Kristian H. Kristensen <hoegsberg@gmail.com>
Date: Wed, 19 Dec 2018 16:57:41 +0000 (-0800)
Subject: drm/msm: Unblock writer if reader closes file
X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=cd70d7ade43d7629edab206fedc686e2eb7257b9;p=openwrt%2Fstaging%2Fblogic.git

drm/msm: Unblock writer if reader closes file

Prevents deadlock when fifo is full and reader closes file.

Signed-off-by: Kristian H. Kristensen <hoegsberg@chromium.org>
Signed-off-by: Rob Clark <robdclark@gmail.com>
---

diff --git a/drivers/gpu/drm/msm/msm_rd.c b/drivers/gpu/drm/msm/msm_rd.c
index 90e9d0a48dc0..d21172933d92 100644
--- a/drivers/gpu/drm/msm/msm_rd.c
+++ b/drivers/gpu/drm/msm/msm_rd.c
@@ -115,7 +115,9 @@ static void rd_write(struct msm_rd_state *rd, const void *buf, int sz)
 		char *fptr = &fifo->buf[fifo->head];
 		int n;
 
-		wait_event(rd->fifo_event, circ_space(&rd->fifo) > 0);
+		wait_event(rd->fifo_event, circ_space(&rd->fifo) > 0 || !rd->open);
+		if (!rd->open)
+			return;
 
 		/* Note that smp_load_acquire() is not strictly required
 		 * as CIRC_SPACE_TO_END() does not access the tail more
@@ -213,7 +215,10 @@ out:
 static int rd_release(struct inode *inode, struct file *file)
 {
 	struct msm_rd_state *rd = inode->i_private;
+
 	rd->open = false;
+	wake_up_all(&rd->fifo_event);
+
 	return 0;
 }