From: Rob Clark <robdcl...@chromium.org>
If the previous thing cat'ing $debugfs/rd left the FIFO full, then
subsequent open could deadlock in rd_write() (because open is blocked,
not giving a chance for read() to consume any data in the FIFO). Also
it is generally a good idea to clear out old data from the FIFO.
Signed-off-by: Rob Clark <robdcl...@chromium.org>
---
drivers/gpu/drm/msm/msm_rd.c | 3 +++
1 file changed, 3 insertions(+)
diff --git a/drivers/gpu/drm/msm/msm_rd.c b/drivers/gpu/drm/msm/msm_rd.c
index a92ffde53f0b..db2f847c8535 100644
--- a/drivers/gpu/drm/msm/msm_rd.c
+++ b/drivers/gpu/drm/msm/msm_rd.c
@@ -196,6 +196,9 @@ static int rd_open(struct inode *inode, struct file *file)
file->private_data = rd;
rd->open = true;
+ /* Reset fifo to clear any previously unread data: */
+ rd->fifo.head = rd->fifo.tail = 0;
+
/* the parsing tools need to know gpu-id to know which
* register database to load.
*
--
2.36.1
