On Sun, 18 Aug 2013, Ming Lei wrote:
> Complete() will be run with interrupt enabled, so change to
> spin_lock_irqsave().
>
> Cc: Alan Stern <st...@rowland.harvard.edu>
> Signed-off-by: Ming Lei <ming....@canonical.com>
> ---
> drivers/usb/core/message.c | 5 +++--
> 1 file changed, 3 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/usb/core/message.c b/drivers/usb/core/message.c
> index 82927e1..8bba734 100644
> --- a/drivers/usb/core/message.c
> +++ b/drivers/usb/core/message.c
> @@ -266,8 +266,9 @@ static void sg_complete(struct urb *urb)
> {
> struct usb_sg_request *io = urb->context;
> int status = urb->status;
> + unsigned long flags;
>
> - spin_lock(&io->lock);
> + spin_lock_irqsave(&io->lock, flags);
>
> /* In 2.5 we require hcds' endpoint queues not to progress after fault
> * reports, until the completion callback (this!) returns. That lets
> @@ -326,7 +327,7 @@ static void sg_complete(struct urb *urb)
> if (!io->count)
> complete(&io->complete);
>
> - spin_unlock(&io->lock);
> + spin_unlock_irqrestore(&io->lock, flags);
> }
As far as I can see, these don't need to disable interrupts. All they
protect against is the code in usb_sg_wait() and usb_sg_cancel(), which
both run in process context.
But will lockdep complain if they don't disable interrupts?
Alan Stern
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