diff options
| author | Rob Clark <robdclark@chromium.org> | 2022-08-07 19:09:01 +0300 |
|---|---|---|
| committer | Greg Kroah-Hartman <gregkh@linuxfoundation.org> | 2022-09-20 13:43:46 +0300 |
| commit | f25a547e7c76673dc7c83fb040c629bbeaf727ce (patch) | |
| tree | f8328e3ceed4746c557acb0fa5077e3f7d01f88e /drivers/gpu/drm | |
| parent | df01ac6582e1049215ccb8e23ff158f376d7e04f (diff) | |
| download | linux-f25a547e7c76673dc7c83fb040c629bbeaf727ce.tar.xz | |
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>
Diffstat (limited to 'drivers/gpu/drm')
| -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 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. * |