Subject: + rtc-s5m-limit-endless-loop-waiting-for-register-update.patch added to -mm tree To: k.kozlowski@xxxxxxxxxxx,a.zummo@xxxxxxxxxxxx,broonie@xxxxxxxxxx,geert@xxxxxxxxxxxxxx,kyungmin.park@xxxxxxxxxxx,lee.jones@xxxxxxxxxx,lgirdwood@xxxxxxxxx,m.szyprowski@xxxxxxxxxxx,sameo@xxxxxxxxxxxxxxx,sbkim73@xxxxxxxxxxx From: akpm@xxxxxxxxxxxxxxxxxxxx Date: Mon, 02 Dec 2013 15:15:41 -0800 The patch titled Subject: rtc: s5m: limit endless loop waiting for register update has been added to the -mm tree. Its filename is rtc-s5m-limit-endless-loop-waiting-for-register-update.patch This patch should soon appear at http://ozlabs.org/~akpm/mmots/broken-out/rtc-s5m-limit-endless-loop-waiting-for-register-update.patch and later at http://ozlabs.org/~akpm/mmotm/broken-out/rtc-s5m-limit-endless-loop-waiting-for-register-update.patch Before you just go and hit "reply", please: a) Consider who else should be cc'ed b) Prefer to cc a suitable mailing list as well c) Ideally: find the original patch on the mailing list and do a reply-to-all to that, adding suitable additional cc's *** Remember to use Documentation/SubmitChecklist when testing your code *** The -mm tree is included into linux-next and is updated there every 3-4 working days ------------------------------------------------------ From: Krzysztof Kozlowski <k.kozlowski@xxxxxxxxxxx> Subject: rtc: s5m: limit endless loop waiting for register update After setting alarm or time the driver is waiting for UDR register to be cleared indicating that registers data have been transferred. Limit the endless loop to only 5 retries. Signed-off-by: Krzysztof Kozlowski <k.kozlowski@xxxxxxxxxxx> Signed-off-by: Kyungmin Park <kyungmin.park@xxxxxxxxxxx> Reviwed-by: Mark Brown <broonie@xxxxxxxxxx> Acked-by: Sangbeom Kim <sbkim73@xxxxxxxxxxx> Cc: Samuel Ortiz <sameo@xxxxxxxxxxxxxxx> Cc: Lee Jones <lee.jones@xxxxxxxxxx> Cc: Liam Girdwood <lgirdwood@xxxxxxxxx> Cc: Alessandro Zummo <a.zummo@xxxxxxxxxxxx> Cc: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx> Cc: Geert Uytterhoeven <geert@xxxxxxxxxxxxxx> Cc: Kyungmin Park <kyungmin.park@xxxxxxxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- drivers/rtc/rtc-s5m.c | 37 +++++++++++++++++++++++++++++++------ 1 file changed, 31 insertions(+), 6 deletions(-) diff -puN drivers/rtc/rtc-s5m.c~rtc-s5m-limit-endless-loop-waiting-for-register-update drivers/rtc/rtc-s5m.c --- a/drivers/rtc/rtc-s5m.c~rtc-s5m-limit-endless-loop-waiting-for-register-update +++ a/drivers/rtc/rtc-s5m.c @@ -28,6 +28,16 @@ #include <linux/mfd/samsung/irq.h> #include <linux/mfd/samsung/rtc.h> +/* + * Maximum number of retries for checking changes in UDR field + * of SEC_RTC_UDR_CON register (to limit possible endless loop). + * + * After writing to RTC registers (setting time or alarm) read the UDR field + * in SEC_RTC_UDR_CON register. UDR is auto-cleared when data have + * been transferred. + */ +#define UDR_READ_RETRY_CNT 5 + struct s5m_rtc_info { struct device *dev; struct sec_pmic_dev *s5m87xx; @@ -84,6 +94,25 @@ static int s5m8767_tm_to_data(struct rtc } } +/* + * Read RTC_UDR_CON register and wait till UDR field is cleared. + * This indicates that time/alarm update ended. + */ +static inline int s5m8767_wait_for_udr_update(struct s5m_rtc_info *info) +{ + int ret, retry = UDR_READ_RETRY_CNT; + unsigned int data; + + do { + ret = regmap_read(info->regmap, SEC_RTC_UDR_CON, &data); + } while (--retry && (data & RTC_UDR_MASK) && !ret); + + if (!retry) + dev_err(info->dev, "waiting for UDR update, reached max number of retries\n"); + + return ret; +} + static inline int s5m8767_rtc_set_time_reg(struct s5m_rtc_info *info) { int ret; @@ -104,9 +133,7 @@ static inline int s5m8767_rtc_set_time_r return ret; } - do { - ret = regmap_read(info->regmap, SEC_RTC_UDR_CON, &data); - } while ((data & RTC_UDR_MASK) && !ret); + ret = s5m8767_wait_for_udr_update(info); return ret; } @@ -133,9 +160,7 @@ static inline int s5m8767_rtc_set_alarm_ return ret; } - do { - ret = regmap_read(info->regmap, SEC_RTC_UDR_CON, &data); - } while ((data & RTC_UDR_MASK) && !ret); + ret = s5m8767_wait_for_udr_update(info); return ret; } _ Patches currently in -mm which might be from k.kozlowski@xxxxxxxxxxx are mfd-rtc-s5m-fix-register-updating-by-adding-regmap-for-rtc.patch rtc-s5m-fix-unsuccesful-irq-request-during-probe.patch rtc-s5m-limit-endless-loop-waiting-for-register-update.patch rtc-s5m-enable-irq-wake-during-suspend.patch mfd-sec-constify-regmap-configs-and-regmap-irqs.patch swap-fix-setting-page_size-blocksize-during-swapoff-swapon-race.patch linux-next.patch -- To unsubscribe from this list: send the line "unsubscribe mm-commits" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html