[PATCH] rtc: stm32: fix comparison warnings
From: Amelie Delaunay <hidden>
Date: 2017-01-16 10:10:25
Also in:
linux-arm-kernel, linux-rtc, lkml
Subsystem:
real time clock (rtc) subsystem, the rest · Maintainers:
Alexandre Belloni, Linus Torvalds
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: 4e64350f42e2 ("rtc: add STM32 RTC driver")
Signed-off-by: Amelie Delaunay <redacted>
---
drivers/rtc/rtc-stm32.c | 6 +++---
1 file changed, 3 insertions(+), 3 deletions(-)
diff --git a/drivers/rtc/rtc-stm32.c b/drivers/rtc/rtc-stm32.c
index 03c97c1..bd57eb1 100644
--- a/drivers/rtc/rtc-stm32.c
+++ b/drivers/rtc/rtc-stm32.c@@ -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"); }
--
1.9.1
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