[PATCH 6.8 115/158] Revert "usb: cdc-wdm: close race between read and workqueue"

Greg Kroah-Hartman
2024-04-23T21:42:25Z

From: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

commit 1607830dadeefc407e4956336d9fcd9e9defd810 upstream.

This reverts commit 339f83612f3a569b194680768b22bf113c26a29d.

It has been found to cause problems in a number of Chromebook devices,
so revert the change until it can be brought back in a safe way.

Link: https://lore.kernel.org/r/385a3519-b45d-48c5-a6fd-a3fdb6bec92f@chromium.org
Reported-by:: Aleksander Morgado <aleksandermj@chromium.org>
Fixes: 339f83612f3a ("usb: cdc-wdm: close race between read and workqueue")
Cc: stable <stable@kernel.org>
Cc: Oliver Neukum <oneukum@suse.com>
Cc: Bjørn Mork <bjorn@mork.no>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
---
drivers/usb/class/cdc-wdm.c | 6 +-----
1 file changed, 1 insertion(+), 5 deletions(-)

--- a/drivers/usb/class/cdc-wdm.c
+++ b/drivers/usb/class/cdc-wdm.c
@@ -485,7 +485,6 @@ out_free_mem:
static int service_outstanding_interrupt(struct wdm_device *desc)
{
int rv = 0;
- int used;

/* submit read urb only if the device is waiting for it */
if (!desc->resp_count || !--desc->resp_count)
@@ -500,10 +499,7 @@ static int service_outstanding_interrupt
goto out;
}

- used = test_and_set_bit(WDM_RESPONDING, &desc->flags);
- if (used)
- goto out;
-
+ set_bit(WDM_RESPONDING, &desc->flags);
spin_unlock_irq(&desc->iuspin);
rv = usb_submit_urb(desc->response, GFP_KERNEL);
spin_lock_irq(&desc->iuspin);