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: Juergen Stuber <[email protected]> Cc: Greg Kroah-Hartman <[email protected]> Cc: [email protected] Signed-off-by: Sebastian Andrzej Siewior <[email protected]> --- drivers/usb/misc/legousbtower.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/usb/misc/legousbtower.c b/drivers/usb/misc/legousbtower.c index bf47bd8bc76f..006cf13b2199 100644 --- a/drivers/usb/misc/legousbtower.c +++ b/drivers/usb/misc/legousbtower.c @@ -722,6 +722,7 @@ static void tower_interrupt_in_callback (struct urb *urb) struct lego_usb_tower *dev = urb->context; int status = urb->status; int retval; + unsigned long flags; lego_usb_tower_debug_data(&dev->udev->dev, __func__, urb->actual_length, urb->transfer_buffer); @@ -740,7 +741,7 @@ static void tower_interrupt_in_callback (struct urb *urb) } if (urb->actual_length > 0) { - spin_lock (&dev->read_buffer_lock); + spin_lock_irqsave(&dev->read_buffer_lock, flags); if (dev->read_buffer_length + urb->actual_length < read_buffer_size) { memcpy (dev->read_buffer + dev->read_buffer_length, dev->interrupt_in_buffer, @@ -753,7 +754,7 @@ static void tower_interrupt_in_callback (struct urb *urb) pr_warn("read_buffer overflow, %d bytes dropped\n", urb->actual_length); } - spin_unlock (&dev->read_buffer_lock); + spin_unlock_irqrestore(&dev->read_buffer_lock, flags); } resubmit: -- 2.18.0 -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
