linux-kernel - [PATCH] rtc: mxc: use spin_lock_irqsave instead of spin_lock

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Date:   Wed,  7 Aug 2019 16:23:10 +0800
From:   Fuqian Huang <huangfq.daxian@...il.com>
To:     unlisted-recipients:; (no To-header on input)
Cc:     Alessandro Zummo <a.zummo@...ertech.it>,
        Alexandre Belloni <alexandre.belloni@...tlin.com>,
        linux-rtc@...r.kernel.org, linux-kernel@...r.kernel.org,
        Fuqian Huang <huangfq.daxian@...il.com>
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 <huangfq.daxian@...il.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