diff options
| author | Rob Clark <robdclark@chromium.org> | 2022-08-07 09:09:01 -0700 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-09-20 11:50:15 +0200 |
| commit | 66b716cbd07b498444df6215c6f9a2e4e6e15887 (patch) | |
| tree | f4a2163a3f35bfcfa97a8b706a085015c0317315 | |
| parent | 61215215bae794670c644bb23074928501466b45 (diff) | |
drm/msm/rd: Fix FIFO-full deadlock
[ Upstream commit 174974d8463b77c2b4065e98513adb204e64de7d ]
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 <robdclark@chromium.org>
Patchwork: https://patchwork.freedesktop.org/patch/496706/
Link: https://lore.kernel.org/r/20220807160901.2353471-2-robdclark@gmail.com
Signed-off-by: Sasha Levin <sashal@kernel.org>
| -rw-r--r-- | drivers/gpu/drm/msm/msm_rd.c | 3 |
1 files changed, 3 insertions, 0 deletions
diff --git a/drivers/gpu/drm/msm/msm_rd.c b/drivers/gpu/drm/msm/msm_rd.c index 4823019eb422..a8a04d8c5ca6 100644 --- a/drivers/gpu/drm/msm/msm_rd.c +++ b/drivers/gpu/drm/msm/msm_rd.c @@ -188,6 +188,9 @@ 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. */ |