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Message-ID: <55FA2FE5.1080900@linaro.org>
Date: Thu, 17 Sep 2015 11:13:41 +0800
From: Pingbo Wen <pingbo.wen@...aro.org>
To: linux-usb@...r.kernel.org
Cc: Y2038 <y2038@...ts.linaro.org>, linux-kernel@...r.kernel.org,
Arnd Bergmann <arnd@...db.de>, Felipe Balbi <balbi@...com>,
stern@...land.harvard.edu
Subject: Re: [PATCH V2] dummy_hcd: replace timeval with timespec64
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@...aro.org>
> Cc: Y2038 <y2038@...ts.linaro.org>
> Cc: linux-kernel@...r.kernel.org
> Cc: Arnd Bergmann <arnd@...db.de>
> Cc: Felipe Balbi <balbi@...com>
> Signed-off-by: WEN Pingbo <pingbo.wen@...aro.org>
> ---
> 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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