Commit 1d70ba3b authored Jan 16, 2017 by Amelie Delaunay Committed by Alexandre Belloni Jan 23, 2017

rtc: stm32: fix comparison warnings



This patches fixes comparison between signed and unsigned values as it
could produce an incorrect result when the signed value is converted to
unsigned:

drivers/rtc/rtc-stm32.c: In function 'stm32_rtc_valid_alrm':
drivers/rtc/rtc-stm32.c:404:21: warning: comparison between signed and unsigned integer expressions [-Wsign-compare]
  if ((((tm->tm_year > cur_year) &&
...

It also fixes comparison always true or false due to the fact that unsigned
value is compared against zero with >= or <:

drivers/rtc/rtc-stm32.c: In function 'stm32_rtc_init':
drivers/rtc/rtc-stm32.c:514:35: warning: comparison of unsigned expression >= 0 is always true [-Wtype-limits]
  for (pred_a = pred_a_max; pred_a >= 0; pred_a-- ) {

drivers/rtc/rtc-stm32.c:530:44: warning: comparison of unsigned expression < 0 is always false [-Wtype-limits]
     (rate - ((pred_a + 1) * (pred_s + 1)) < 0) ?

Fixes: 4e64350f ("rtc: add STM32 RTC driver")
Signed-off-by: Amelie Delaunay <amelie.delaunay@st.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>

parent a560c527

drivers/rtc/rtc-stm32.c

+3 −3

Original line number	Diff line number	Diff line
		@@ -383,7 +383,7 @@ static int stm32_rtc_alarm_irq_enable(struct device *dev, unsigned int enabled)

		static int stm32_rtc_valid_alrm(struct stm32_rtc rtc, struct rtc_time tm)
		{
		unsigned int cur_day, cur_mon, cur_year, cur_hour, cur_min, cur_sec;
		int cur_day, cur_mon, cur_year, cur_hour, cur_min, cur_sec;
		unsigned int dr = readl_relaxed(rtc->base + STM32_RTC_DR);
		unsigned int tr = readl_relaxed(rtc->base + STM32_RTC_TR);

		@@ -509,7 +509,7 @@ static int stm32_rtc_init(struct platform_device *pdev,
		pred_a_max = STM32_RTC_PRER_PRED_A >> STM32_RTC_PRER_PRED_A_SHIFT;
		pred_s_max = STM32_RTC_PRER_PRED_S >> STM32_RTC_PRER_PRED_S_SHIFT;

		for (pred_a = pred_a_max; pred_a >= 0; pred_a--) {
		for (pred_a = pred_a_max; pred_a + 1 > 0; pred_a--) {
		pred_s = (rate / (pred_a + 1)) - 1;

		if (((pred_s + 1) * (pred_a + 1)) == rate)
		@@ -525,7 +525,7 @@ static int stm32_rtc_init(struct platform_device *pdev,
		pred_s = (rate / (pred_a + 1)) - 1;

		dev_warn(&pdev->dev, "ck_rtc is %s\n",
		(rate - ((pred_a + 1) * (pred_s + 1)) < 0) ?
		(rate < ((pred_a + 1) * (pred_s + 1))) ?
		"fast" : "slow");
		}

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