diff options
| author | Maxime Ripard <maxime.ripard@free-electrons.com> | 2017-01-23 13:41:47 +0300 |
|---|---|---|
| committer | Alexandre Belloni <alexandre.belloni@free-electrons.com> | 2017-02-01 14:42:39 +0300 |
| commit | a9422a19ce270a22fc520f2278fb7e80c58be508 (patch) | |
| tree | 6507b1553c16b5b20a87eed7b7015e3b07cfa910 /drivers | |
| parent | 3753941475ae6501dcd1e41832bd0e6c35247d6a (diff) | |
| download | linux-a9422a19ce270a22fc520f2278fb7e80c58be508.tar.xz | |
rtc: sun6i: Add some locking
Some registers have a read-modify-write access pattern that are not atomic.
Add some locking to prevent from concurrent accesses.
Cc: stable@vger.kernel.org
Acked-by: Chen-Yu Tsai <wens@csie.org>
Signed-off-by: Maxime Ripard <maxime.ripard@free-electrons.com>
Signed-off-by: Alexandre Belloni <alexandre.belloni@free-electrons.com>
Diffstat (limited to 'drivers')
| -rw-r--r-- | drivers/rtc/rtc-sun6i.c | 17 |
1 files changed, 15 insertions, 2 deletions
diff --git a/drivers/rtc/rtc-sun6i.c b/drivers/rtc/rtc-sun6i.c index a6136cb99851..72086f0c0782 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(&chip->lock); platform_set_drvdata(pdev, chip); chip->dev = &pdev->dev; |