| Message ID | 1484561333-12087-1-git-send-email-amelie.delaunay@st.com (mailing list archive) |
|---|---|
| State | New, archived |
| Headers | show |
On 16/01/2017 at 11:08:53 +0100, Amelie Delaunay wrote : > 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 <amelie.delaunay@st.com> > --- > drivers/rtc/rtc-stm32.c | 6 +++--- > 1 file changed, 3 insertions(+), 3 deletions(-) > Applied, thanks.
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"); }
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 <amelie.delaunay@st.com> --- drivers/rtc/rtc-stm32.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-)