Commit 174974d8 authored by Rob Clark's avatar Rob Clark
Browse files

drm/msm/rd: Fix FIFO-full deadlock 



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: default avatarRob Clark <robdclark@chromium.org>
Patchwork: https://patchwork.freedesktop.org/patch/496706/
Link: https://lore.kernel.org/r/20220807160901.2353471-2-robdclark@gmail.com
parent 02b9f263

drivers/gpu/drm/msm/msm_rd.c

+3 −0
Original line number Diff line number Diff line
@@ -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.

	 *