Re: [PATCH V2] dummy_hcd: replace timeval with timespec64

[Pingbo Wen]

add Alan Stern

On Thursday, September 17, 2015 11:09 AM, WEN Pingbo wrote:
> The millisecond of the last second will be normal if tv_sec is
> overflowed. But for y2038 consistency and demonstration purpose,
> and avoiding further risks, we need to remove 'timeval' in this
> driver, to avoid similair problems.
> 
> V2 Updates:
> - using monotonic time here by replacing getnstimeofday() with
>   ktime_get_ts64(), to avoid leap second issues. The frame time in USB
>   is always 1ms, no matter what speed, so ktime_get_ts64() have enough
>   resolution to cover this.
> - using NSEC_PER_MSEC instead of hard code.
> 
> Signed-off-by: Pingbo Wen <pingbo.wen@xxxxxxxxxx>
> Cc: Y2038 <y2038@xxxxxxxxxxxxxxxx>
> Cc: linux-kernel@xxxxxxxxxxxxxxx
> Cc: Arnd Bergmann <arnd@xxxxxxxx>
> Cc: Felipe Balbi <balbi@xxxxxx>
> Signed-off-by: WEN Pingbo <pingbo.wen@xxxxxxxxxx>
> ---
>  drivers/usb/gadget/udc/dummy_hcd.c | 6 +++---
>  1 file changed, 3 insertions(+), 3 deletions(-)
> 
> diff --git a/drivers/usb/gadget/udc/dummy_hcd.c b/drivers/usb/gadget/udc/dummy_hcd.c
> index 1379ad4..6d1ed35 100644
> --- a/drivers/usb/gadget/udc/dummy_hcd.c
> +++ b/drivers/usb/gadget/udc/dummy_hcd.c
> @@ -833,10 +833,10 @@ static const struct usb_ep_ops dummy_ep_ops = {
>  /* there are both host and device side versions of this call ... */
>  static int dummy_g_get_frame(struct usb_gadget *_gadget)
>  {
> -	struct timeval	tv;
> +	struct timespec64 tv;
>  
> -	do_gettimeofday(&tv);
> -	return tv.tv_usec / 1000;
> +	ktime_get_ts64(&tv);
> +	return tv.tv_nsec / NSEC_PER_MSEC;
>  }
>  
>  static int dummy_wakeup(struct usb_gadget *_gadget)
> 
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