Re: [PATCH 2/2] rtc: rtc-wm8350: Add support for WM8350 RTC

[Andrew Morton <akpm@linux-foundation.org>]

On Mon, 20 Oct 2008 20:35:18 +0100 Mark Brown <broonie@opensource.wolfsonmicro.com> wrote:

> +static int wm8350_rtc_stop_alarm(struct wm8350 *wm8350)
> +{
> +	int retries = WM8350_SET_ALM_RETRIES;
> +	u16 rtc_ctrl;
> +	int ret;
> +
> +	/* Set RTC_SET to stop the clock */
> +	ret = wm8350_set_bits(wm8350, WM8350_RTC_TIME_CONTROL,
> +			      WM8350_RTC_ALMSET);
> +	if (ret < 0)
> +		return ret;
> +
> +	/* Wait until confirmation of stopping */
> +	do {
> +		rtc_ctrl = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL);
> +		schedule_timeout_interruptible(msecs_to_jiffies(1));

If the calling process has signal_pending() (eg: someone typed ^C) then
schedule_timeout_interruptible() will return immediately.

> +	} while (retries-- && !(rtc_ctrl & WM8350_RTC_ALMSTS));
> +
> +	if (!(rtc_ctrl & WM8350_RTC_ALMSTS))
> +		return -ETIMEDOUT;

And the driver will incorrectly return -ETIMEDOUT.

> +	return 0;
> +}
> +
> +static int wm8350_rtc_start_alarm(struct wm8350 *wm8350)
> +{
> +	int ret;
> +	int retries = WM8350_SET_ALM_RETRIES;
> +	u16 rtc_ctrl;
> +
> +	ret = wm8350_clear_bits(wm8350, WM8350_RTC_TIME_CONTROL,
> +				WM8350_RTC_ALMSET);
> +	if (ret < 0)
> +		return ret;
> +
> +	/* Wait until confirmation */
> +	do {
> +		rtc_ctrl = wm8350_reg_read(wm8350, WM8350_RTC_TIME_CONTROL);
> +		schedule_timeout_interruptible(msecs_to_jiffies(1));
> +	} while (retries-- && rtc_ctrl & WM8350_RTC_ALMSTS);
> +
> +	if (rtc_ctrl & WM8350_RTC_ALMSTS)
> +		return -ETIMEDOUT;

ditto.

> +	return 0;
> +}

I'll switch those to schedule_timeout_uninterruptible(), OK?