This is a note to let you know that I've just added the patch titled rtc: sun6i: Add some locking to the 4.10-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: rtc-sun6i-add-some-locking.patch and it can be found in the queue-4.10 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let <stable@xxxxxxxxxxxxxxx> know about it. >From a9422a19ce270a22fc520f2278fb7e80c58be508 Mon Sep 17 00:00:00 2001 From: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx> Date: Mon, 23 Jan 2017 11:41:47 +0100 Subject: rtc: sun6i: Add some locking From: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx> commit a9422a19ce270a22fc520f2278fb7e80c58be508 upstream. Some registers have a read-modify-write access pattern that are not atomic. Add some locking to prevent from concurrent accesses. Acked-by: Chen-Yu Tsai <wens@xxxxxxxx> Signed-off-by: Maxime Ripard <maxime.ripard@xxxxxxxxxxxxxxxxxx> Signed-off-by: Alexandre Belloni <alexandre.belloni@xxxxxxxxxxxxxxxxxx> Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx> --- drivers/rtc/rtc-sun6i.c | 17 +++++++++++++++-- 1 file changed, 15 insertions(+), 2 deletions(-) --- 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(in 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, str 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, str 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 devi 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 platfo chip = devm_kzalloc(&pdev->dev, sizeof(*chip), GFP_KERNEL); if (!chip) return -ENOMEM; + spin_lock_init(&chip->lock); platform_set_drvdata(pdev, chip); chip->dev = &pdev->dev; Patches currently in stable-queue which might be from maxime.ripard@xxxxxxxxxxxxxxxxxx are queue-4.10/rtc-sun6i-disable-the-build-as-a-module.patch queue-4.10/rtc-sun6i-add-some-locking.patch queue-4.10/rtc-sun6i-switch-to-the-external-oscillator.patch