The rtc user must wait at least 1 sec between each time/calandar update (see atmel's datasheet chapter "Updating Time/Calendar").
Use the 1Hz interrupt to update the at91_rtc_upd_rdy flag and wait for the at91_rtc_wait_upd_rdy event if the rtc is not ready. Signed-off-by: Boris BREZILLON <[email protected]> Reported-by: Bryan Evenson <[email protected]> --- Hello Bryan, I reproduced your bug (using your script) and this patch seems to fix the problem. Could you try it and let me know if it works for you ? Best Regards, Boris drivers/rtc/rtc-at91rm9200.c | 14 +++++++++++++- 1 file changed, 13 insertions(+), 1 deletion(-) diff --git a/drivers/rtc/rtc-at91rm9200.c b/drivers/rtc/rtc-at91rm9200.c index 3281c90..e3fe54c 100644 --- a/drivers/rtc/rtc-at91rm9200.c +++ b/drivers/rtc/rtc-at91rm9200.c @@ -48,11 +48,13 @@ struct at91_rtc_config { static const struct at91_rtc_config *at91_rtc_config; static DECLARE_COMPLETION(at91_rtc_updated); +static DECLARE_COMPLETION(at91_rtc_wait_upd_rdy); static unsigned int at91_alarm_year = AT91_RTC_EPOCH; static void __iomem *at91_rtc_regs; static int irq; static DEFINE_SPINLOCK(at91_rtc_lock); static u32 at91_rtc_shadow_imr; +static bool at91_rtc_upd_rdy; static void at91_rtc_write_ier(u32 mask) { @@ -161,6 +163,8 @@ static int at91_rtc_settime(struct device *dev, struct rtc_time *tm) 1900 + tm->tm_year, tm->tm_mon, tm->tm_mday, tm->tm_hour, tm->tm_min, tm->tm_sec); + wait_for_completion(&at91_rtc_wait_upd_rdy); + /* Stop Time/Calendar from counting */ cr = at91_rtc_read(AT91_RTC_CR); at91_rtc_write(AT91_RTC_CR, cr | AT91_RTC_UPDCAL | AT91_RTC_UPDTIM); @@ -183,6 +187,7 @@ static int at91_rtc_settime(struct device *dev, struct rtc_time *tm) /* Restart Time/Calendar */ cr = at91_rtc_read(AT91_RTC_CR); + at91_rtc_upd_rdy = 0; at91_rtc_write(AT91_RTC_CR, cr & ~(AT91_RTC_UPDCAL | AT91_RTC_UPDTIM)); return 0; @@ -290,8 +295,13 @@ static irqreturn_t at91_rtc_interrupt(int irq, void *dev_id) if (rtsr) { /* this interrupt is shared! Is it ours? */ if (rtsr & AT91_RTC_ALARM) events |= (RTC_AF | RTC_IRQF); - if (rtsr & AT91_RTC_SECEV) + if (rtsr & AT91_RTC_SECEV) { events |= (RTC_UF | RTC_IRQF); + if (!at91_rtc_upd_rdy) { + at91_rtc_upd_rdy = 1; + complete(&at91_rtc_wait_upd_rdy); + } + } if (rtsr & AT91_RTC_ACKUPD) complete(&at91_rtc_updated); @@ -413,6 +423,8 @@ static int __init at91_rtc_probe(struct platform_device *pdev) return PTR_ERR(rtc); platform_set_drvdata(pdev, rtc); + /* Enable 1Hz events */ + at91_rtc_write_ier(AT91_RTC_SECEV); dev_info(&pdev->dev, "AT91 Real Time Clock driver.\n"); return 0; } -- 1.8.3.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
