From: Rob Clark <robdclark@xxxxxxxxxxxx> 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@xxxxxxxxxxxx> --- 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
