This is a note to let you know that I've just added the patch titled
rtc: sun6i: Add some locking
to the 4.4-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-4.4 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-4.4/rtc-sun6i-add-some-locking.patch
queue-4.4/rtc-sun6i-switch-to-the-external-oscillator.patch