[PATCH] rtc: mxc: use spin_lock_irqsave instead of spin_lock_irq in IRQ context

[PATCH] rtc: mxc: use spin_lock_irqsave instead of spin_lock_irq in IRQ context

[Fuqian Huang]

As spin_unlock_irq will enable interrupts.
mxc_rtc_irq_enable is called from interrupt handler mxc_rtc_interrupt.
Interrupts are enabled in interrupt handler.
Use spin_lock_irqsave/spin_unlock_irqrestore instead of spin_(un)lock_irq
in IRQ context to avoid this.

Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
---
 drivers/rtc/rtc-mxc.c | 5 +++--
 1 file changed, 3 insertions(+), 2 deletions(-)

diff --git a/drivers/rtc/rtc-mxc.c b/drivers/rtc/rtc-mxc.c
index e697e96612bb..902d57dcd0d4 100644
--- a/drivers/rtc/rtc-mxc.c
+++ b/drivers/rtc/rtc-mxc.c
@@ -184,8 +184,9 @@ static void mxc_rtc_irq_enable(struct device *dev, unsigned int bit,
 	struct rtc_plat_data *pdata = dev_get_drvdata(dev);
 	void __iomem *ioaddr = pdata->ioaddr;
 	u32 reg;
+	unsigned long flags;
 
-	spin_lock_irq(&pdata->rtc->irq_lock);
+	spin_lock_irqsave(&pdata->rtc->irq_lock, flags);
 	reg = readw(ioaddr + RTC_RTCIENR);
 
 	if (enabled)
@@ -194,7 +195,7 @@ static void mxc_rtc_irq_enable(struct device *dev, unsigned int bit,
 		reg &= ~bit;
 
 	writew(reg, ioaddr + RTC_RTCIENR);
-	spin_unlock_irq(&pdata->rtc->irq_lock);
+	spin_unlock_irqrestore(&pdata->rtc->irq_lock, flags);
 }
 
 /* This function is the RTC interrupt service routine. */
-- 
2.11.0

Re: [PATCH] rtc: mxc: use spin_lock_irqsave instead of spin_lock_irq in IRQ context

[Alexandre Belloni]

On 07/08/2019 16:23:10+0800, Fuqian Huang wrote:
> As spin_unlock_irq will enable interrupts.
> mxc_rtc_irq_enable is called from interrupt handler mxc_rtc_interrupt.
> Interrupts are enabled in interrupt handler.
> Use spin_lock_irqsave/spin_unlock_irqrestore instead of spin_(un)lock_irq
> in IRQ context to avoid this.
> 
> Signed-off-by: Fuqian Huang <huangfq.daxian@gmail.com>
> ---
>  drivers/rtc/rtc-mxc.c | 5 +++--
>  1 file changed, 3 insertions(+), 2 deletions(-)
> 
Applied, thanks.

-- 
Alexandre Belloni, Bootlin
Embedded Linux and Kernel engineering
https://bootlin.com