Some registers have a read-modify-write access pattern that are not atomic.
Add some locking to prevent from concurrent accesses. Cc: [email protected] Acked-by: Chen-Yu Tsai <[email protected]> Signed-off-by: Maxime Ripard <[email protected]> --- drivers/rtc/rtc-sun6i.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) diff --git a/drivers/rtc/rtc-sun6i.c b/drivers/rtc/rtc-sun6i.c index a6136cb99851..5527f5eb597b 100644 --- a/drivers/rtc/rtc-sun6i.c +++ b/drivers/rtc/rtc-sun6i.c @@ -114,13 +114,17 @@ struct sun6i_rtc_dev { void __iomem *base; int irq; unsigned long alarm; + + spinlock_t lock; }; static irqreturn_t sun6i_rtc_alarmirq(int irq, void *id) { struct sun6i_rtc_dev *chip = (struct sun6i_rtc_dev *) id; + irqreturn_t ret = IRQ_NONE; u32 val; + spin_lock(&chip->lock); val = readl(chip->base + SUN6I_ALRM_IRQ_STA); if (val & SUN6I_ALRM_IRQ_STA_CNT_IRQ_PEND) { @@ -129,10 +133,11 @@ static irqreturn_t sun6i_rtc_alarmirq(int irq, void *id) rtc_update_irq(chip->rtc, 1, RTC_AF | RTC_IRQF); - return IRQ_HANDLED; + ret = IRQ_HANDLED; } + spin_unlock(&chip->lock); - return IRQ_NONE; + return ret; } static void sun6i_rtc_setaie(int to, struct sun6i_rtc_dev *chip) @@ -140,6 +145,7 @@ static void sun6i_rtc_setaie(int to, struct sun6i_rtc_dev *chip) u32 alrm_val = 0; u32 alrm_irq_val = 0; u32 alrm_wake_val = 0; + unsigned long flags; if (to) { alrm_val = SUN6I_ALRM_EN_CNT_EN; @@ -150,9 +156,11 @@ static void sun6i_rtc_setaie(int to, struct sun6i_rtc_dev *chip) chip->base + SUN6I_ALRM_IRQ_STA); } + spin_lock_irqsave(&chip->lock, flags); writel(alrm_val, chip->base + SUN6I_ALRM_EN); writel(alrm_irq_val, chip->base + SUN6I_ALRM_IRQ_EN); writel(alrm_wake_val, chip->base + SUN6I_ALARM_CONFIG); + spin_unlock_irqrestore(&chip->lock, flags); } static int sun6i_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm) @@ -191,11 +199,15 @@ static int sun6i_rtc_gettime(struct device *dev, struct rtc_time *rtc_tm) static int sun6i_rtc_getalarm(struct device *dev, struct rtc_wkalrm *wkalrm) { struct sun6i_rtc_dev *chip = dev_get_drvdata(dev); + unsigned long flags; u32 alrm_st; u32 alrm_en; + spin_lock_irqsave(&chip->lock, flags); alrm_en = readl(chip->base + SUN6I_ALRM_IRQ_EN); alrm_st = readl(chip->base + SUN6I_ALRM_IRQ_STA); + spin_unlock_irqrestore(&chip->lock, flags); + wkalrm->enabled = !!(alrm_en & SUN6I_ALRM_EN_CNT_EN); wkalrm->pending = !!(alrm_st & SUN6I_ALRM_EN_CNT_EN); rtc_time_to_tm(chip->alarm, &wkalrm->time); @@ -356,6 +368,7 @@ static int sun6i_rtc_probe(struct platform_device *pdev) chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL); if (!chip) return -ENOMEM; + spin_lock_init(&rtc->lock); platform_set_drvdata(pdev, chip); chip->dev = &pdev->dev; -- git-series 0.8.11 -- You received this message because you are subscribed to "rtc-linux". Membership options at http://groups.google.com/group/rtc-linux . Please read http://groups.google.com/group/rtc-linux/web/checklist before submitting a driver. --- You received this message because you are subscribed to the Google Groups "rtc-linux" group. To unsubscribe from this group and stop receiving emails from it, send an email to [email protected]. For more options, visit https://groups.google.com/d/optout.
