From: Oliver Neukum oneukum@suse.com
commit 0afccd7601514c4b83d8cc58c740089cc447051d upstream.
Suspend increments a counter, then kills the URBs, then kills the scheduled work. The scheduled work, however, may reschedule the URBs. Fix this by having the work check the counter.
Signed-off-by: Oliver Neukum oneukum@suse.com Cc: stable stable@vger.kernel.org Tested-by: Jonas Karlsson jonas.karlsson@actia.se Link: https://lore.kernel.org/r/20200415151358.32664-1-oneukum@suse.com Signed-off-by: Greg Kroah-Hartman gregkh@linuxfoundation.org --- drivers/usb/class/cdc-acm.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/usb/class/cdc-acm.c b/drivers/usb/class/cdc-acm.c index 6e0b418..162ef29 100644 --- a/drivers/usb/class/cdc-acm.c +++ b/drivers/usb/class/cdc-acm.c @@ -563,14 +563,14 @@ static void acm_softint(struct work_struct *work) struct acm *acm = container_of(work, struct acm, work);
if (test_bit(EVENT_RX_STALL, &acm->flags)) { - if (!(usb_autopm_get_interface(acm->data))) { + smp_mb(); /* against acm_suspend() */ + if (!acm->susp_count) { for (i = 0; i < acm->rx_buflimit; i++) usb_kill_urb(acm->read_urbs[i]); usb_clear_halt(acm->dev, acm->in); acm_submit_read_urbs(acm, GFP_KERNEL); - usb_autopm_put_interface(acm->data); + clear_bit(EVENT_RX_STALL, &acm->flags); } - clear_bit(EVENT_RX_STALL, &acm->flags); }
if (test_and_clear_bit(EVENT_TTY_WAKEUP, &acm->flags))