Subject: Re: [PATCH 17/50] USB: serial: sierra: spin_lock in complete() cleanup

From: Sergei Shtylyov <[email-masked]>
Date: Thu, 11 Jul 2013 17:02:03 +0400

Hello.

On 11-07-2013 13:05, Ming Lei wrote:

> Complete() will be run with interrupt enabled, so change to
> spin_lock_irqsave().

> Cc: Johan Hovold <[email-masked]>
> Signed-off-by: Ming Lei <[email-masked]>
> ---
>   drivers/usb/serial/sierra.c |    9 +++++----
>   1 file changed, 5 insertions(+), 4 deletions(-)

> diff --git a/drivers/usb/serial/sierra.c b/drivers/usb/serial/sierra.c
> index de958c5..e79b6ad 100644
> --- a/drivers/usb/serial/sierra.c
> +++ b/drivers/usb/serial/sierra.c
> @@ -433,6 +433,7 @@ static void sierra_outdat_callback(struct urb *urb)
>   	struct sierra_port_private *portdata = usb_get_serial_port_data(port);
>   	struct sierra_intf_private *intfdata;
>   	int status = urb->status;
> +	unsigned long flags;
>
>   	intfdata = port->serial->private;
>
> @@ -443,12 +444,12 @@ static void sierra_outdat_callback(struct urb *urb)
>   		dev_dbg(&port->dev, "%s - nonzero write bulk status "
>   		    "received: %d\n", __func__, status);
>
> -	spin_lock(&portdata->lock);
> +	spin_lock_irqsave(&portdata->lock, flags);
>   	--portdata->outstanding_urbs;
> -	spin_unlock(&portdata->lock);
> -	spin_lock(&intfdata->susp_lock);
> +	spin_unlock_irqrestore(&portdata->lock, flags);
> +	spin_lock_irqsave(&intfdata->susp_lock, flags);

     You are allowing an interrupt enabled window where previously it 
wasn't possible. Why notleave these 2 lines as is?

>   	--intfdata->in_flight;
> -	spin_unlock(&intfdata->susp_lock);
> +	spin_unlock_irqrestore(&intfdata->susp_lock, flags);
>
>   	usb_serial_port_softint(port);
>   }

WBR, Sergei