Re: [PATCH RESEND] HID: multitouch: Add memory barriers
From: Greg KH <gregkh@linuxfoundation.org>
Date: 2022-08-17 11:59:40
Also in:
stable
On Wed, Aug 17, 2022 at 11:32:48AM +0000, Andri Yngvason wrote:
This fixes a race with the release-timer by adding acquire/release barrier semantics.
What race?
quoted hunk ↗ jump to hunk
I noticed that contacts were sometimes sticking, even with the "sticky fingers" quirk enabled. This fixes that problem. Cc: stable@vger.kernel.org Signed-off-by: Andri Yngvason <redacted> --- drivers/hid/hid-multitouch.c | 8 ++++---- 1 file changed, 4 insertions(+), 4 deletions(-)diff --git a/drivers/hid/hid-multitouch.c b/drivers/hid/hid-multitouch.c index 2e72922e36f5..91a4d3fc30e0 100644 --- a/drivers/hid/hid-multitouch.c +++ b/drivers/hid/hid-multitouch.c@@ -1186,7 +1186,7 @@ static void mt_touch_report(struct hid_device *hid, int contact_count = -1; /* sticky fingers release in progress, abort */ - if (test_and_set_bit(MT_IO_FLAGS_RUNNING, &td->mt_io_flags)) + if (test_and_set_bit_lock(MT_IO_FLAGS_RUNNING, &td->mt_io_flags))
So this is now a lock? Why not just use a real lock instead? thanks, greg k-h