4.20-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 <hoegsberg@xxxxxxxxxxxx>
Signed-off-by: Rob Clark <robdclark@xxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
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 0c2c8d2c631f3..25fc161ab6181 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 @@ 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
