2019-08-07 08:35:20

by Fuqian Huang

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

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 <[email protected]>
---
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

2019-08-12 21:06:20

by Alexandre Belloni

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

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 <[email protected]>
> ---
> 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