Re: [PATCH 1/2] usb: usbtest: Add timetout to simple_io()

[Huang Rui]

Hi Roger,

On Wed, Dec 18, 2013 at 03:40:10PM +0530, Roger Quadros wrote:
> Without a timetout some tests e.g. test_halt() can remain stuck forever.
> 
> Signed-off-by: Roger Quadros <rogerq@xxxxxx>
> Reviewed-by: Felipe Balbi <balbi@xxxxxx>
> ---
>  drivers/usb/misc/usbtest.c | 14 +++++++++++---
>  1 file changed, 11 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/usb/misc/usbtest.c b/drivers/usb/misc/usbtest.c
> index b415282..6294e1b 100644
> --- a/drivers/usb/misc/usbtest.c
> +++ b/drivers/usb/misc/usbtest.c
> @@ -10,6 +10,7 @@
>  
>  #include <linux/usb.h>
>  
> +#define SIMPLE_IO_TIMEOUT	10000	/* in milliseconds */
>  

Only one question, how do you confirm the timeout value?

Thanks,
Rui

>  /*-------------------------------------------------------------------------*/
>  
> @@ -366,6 +367,7 @@ static int simple_io(
>  	int			max = urb->transfer_buffer_length;
>  	struct completion	completion;
>  	int			retval = 0;
> +	unsigned long		expire;
>  
>  	urb->context = &completion;
>  	while (retval == 0 && iterations-- > 0) {
> @@ -378,9 +380,15 @@ static int simple_io(
>  		if (retval != 0)
>  			break;
>  
> -		/* NOTE:  no timeouts; can't be broken out of by interrupt */
> -		wait_for_completion(&completion);
> -		retval = urb->status;
> +		expire = msecs_to_jiffies(SIMPLE_IO_TIMEOUT);
> +		if (!wait_for_completion_timeout(&completion, expire)) {
> +			usb_kill_urb(urb);
> +			retval = (urb->status == -ENOENT ?
> +				  -ETIMEDOUT : urb->status);
> +		} else {
> +			retval = urb->status;
> +		}
> +
>  		urb->dev = udev;
>  		if (retval == 0 && usb_pipein(urb->pipe))
>  			retval = simple_check_buf(tdev, urb);
> -- 
> 1.8.3.2
> 
> 

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