drm/msm: Unblock writer if reader closes file

[ Upstream commit 99c66bc051e7407fe0bf0607b142ec0be1a1d1dd ]

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>
Signed-off-by: Sasha Levin <sashal@kernel.org>

diff --git a/drivers/gpu/drm/msm/msm_rd.c b/drivers/gpu/drm/msm/msm_rd.c
index ec56794ad0399277693b9185c75b6abcf9241e4a..bdce1c9434c6c4134a9d85a128b5f809e943a364 100644 (file)
--- a/drivers/gpu/drm/msm/msm_rd.c
+++ b/drivers/gpu/drm/msm/msm_rd.c
@@ -109,7 +109,9 @@ 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
@@ -207,7 +209,10 @@ 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;
 }