HID: multitouch: Add memory barriers

This fixes broken atomic checks which cause a race between the
release-timer and processing of hid input.

I noticed that contacts were sometimes sticking, even with the "sticky
fingers" quirk enabled. This fixes that problem.

Cc: stable@vger.kernel.org
Fixes: 9609827458 ("HID: multitouch: optimize the sticky fingers timer")
Signed-off-by: Andri Yngvason <andri@yngvason.is>
Signed-off-by: Benjamin Tissoires <benjamin.tissoires@redhat.com>
Link: https://lore.kernel.org/r/20220907150159.2285460-1-andri@yngvason.is
This commit is contained in:
Andri Yngvason 2022-09-07 15:01:59 +00:00 committed by Benjamin Tissoires
parent a1f764268f
commit be6e2b5734

View File

@ -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))
return;
scantime = *app->scantime;
@ -1267,7 +1267,7 @@ static void mt_touch_report(struct hid_device *hid,
del_timer(&td->release_timer);
}
clear_bit(MT_IO_FLAGS_RUNNING, &td->mt_io_flags);
clear_bit_unlock(MT_IO_FLAGS_RUNNING, &td->mt_io_flags);
}
static int mt_touch_input_configured(struct hid_device *hdev,
@ -1699,11 +1699,11 @@ static void mt_expired_timeout(struct timer_list *t)
* An input report came in just before we release the sticky fingers,
* it will take care of the sticky fingers.
*/
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))
return;
if (test_bit(MT_IO_FLAGS_PENDING_SLOTS, &td->mt_io_flags))
mt_release_contacts(hdev);
clear_bit(MT_IO_FLAGS_RUNNING, &td->mt_io_flags);
clear_bit_unlock(MT_IO_FLAGS_RUNNING, &td->mt_io_flags);
}
static int mt_probe(struct hid_device *hdev, const struct hid_device_id *id)