@@ -276,6 +276,7 @@ static void acm_process_notification(struct acm *acm, unsigned char *buf)
{
int newctrl;
int difference;
+ unsigned long flags;
struct usb_cdc_notification *dr = (struct usb_cdc_notification *)buf;
unsigned char *data = buf + sizeof(struct usb_cdc_notification);
@@ -303,7 +304,7 @@ static void acm_process_notification(struct acm *acm, unsigned char *buf)
}
difference = acm->ctrlin ^ newctrl;
- spin_lock(&acm->read_lock);
+ spin_lock_irqsave(&acm->read_lock, flags);
acm->ctrlin = newctrl;
acm->oldcount = acm->iocount;
@@ -321,7 +322,7 @@ static void acm_process_notification(struct acm *acm, unsigned char *buf)
acm->iocount.parity++;
if (difference & ACM_CTRL_OVERRUN)
acm->iocount.overrun++;
- spin_unlock(&acm->read_lock);
+ spin_unlock_irqrestore(&acm->read_lock, flags);
if (difference)
wake_up_all(&acm->wioctl);
The USB completion callback does not disable interrupts while acquiring the lock. We want to remove the local_irq_disable() invocation from __usb_hcd_giveback_urb() and therefore it is required for the callback handler to disable the interrupts while acquiring the lock. The callback may be invoked either in IRQ or BH context depending on the USB host controller. Use the _irqsave() variant of the locking primitives. Cc: Oliver Neukum <oneukum@suse.com> Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org> Signed-off-by: Sebastian Andrzej Siewior <bigeasy@linutronix.de> --- drivers/usb/class/cdc-acm.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-)