4.9-stable review patch.  If anyone has any objections, please let me know.

------------------

[ Upstream commit 99c66bc051e7407fe0bf0607b142ec0be1a1d1dd ]

Prevents deadlock when fifo is full and reader closes file.

Signed-off-by: Kristian H. Kristensen <[email protected]>
Signed-off-by: Rob Clark <[email protected]>
Signed-off-by: Sasha Levin <[email protected]>
---
 drivers/gpu/drm/msm/msm_rd.c | 7 ++++++-
 1 file changed, 6 insertions(+), 1 deletion(-)

diff --git a/drivers/gpu/drm/msm/msm_rd.c b/drivers/gpu/drm/msm/msm_rd.c
index 8487f461f05f3..4823019eb422b 100644
--- a/drivers/gpu/drm/msm/msm_rd.c
+++ b/drivers/gpu/drm/msm/msm_rd.c
@@ -112,7 +112,9 @@ 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;
 
                n = min(sz, circ_space_to_end(&rd->fifo));
                memcpy(fptr, ptr, n);
@@ -202,7 +204,10 @@ static int rd_open(struct inode *inode, struct file *file)
 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;
 }
 
-- 
2.19.1



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