[PATCH 0/6] spin lock usage optimization for RTC drivers

[PATCH 0/6] spin lock usage optimization for RTC drivers

[Xiaofei Tan]

Replace spin_lock_irqsave with spin_lock in hard IRQ of RTC drivers.
There is no function changes, but may speed up if interrupt happen
too often.

Xiaofei Tan (6):
  rtc: cmos: Replace spin_lock_irqsave with spin_lock in hard IRQ
  rtc: pm8xxx: Replace spin_lock_irqsave with spin_lock in hard IRQ
  rtc: r7301: Replace spin_lock_irqsave with spin_lock in hard IRQ
  rtc: tegra: Replace spin_lock_irqsave with spin_lock in hard IRQ
  rtc: mxc: Replace spin_lock_irqsave with spin_lock in hard IRQ
  rtc: mxc_v2: Replace spin_lock_irqsave with spin_lock in hard IRQ

 drivers/rtc/rtc-cmos.c   | 5 ++---
 drivers/rtc/rtc-mxc.c    | 5 ++---
 drivers/rtc/rtc-mxc_v2.c | 7 +++----
 drivers/rtc/rtc-pm8xxx.c | 9 ++++-----
 drivers/rtc/rtc-r7301.c  | 5 ++---
 drivers/rtc/rtc-tegra.c  | 6 +++---
 6 files changed, 16 insertions(+), 21 deletions(-)

-- 
2.8.1

[PATCH 1/6] rtc: cmos: Replace spin_lock_irqsave with spin_lock in hard IRQ

[Xiaofei Tan]

It is redundant to do irqsave and irqrestore in hardIRQ context, where
it has been in a irq-disabled context.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
---
 drivers/rtc/rtc-cmos.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/rtc/rtc-cmos.c b/drivers/rtc/rtc-cmos.c
index 68a9ac6..d46f59a 100644
--- a/drivers/rtc/rtc-cmos.c
+++ b/drivers/rtc/rtc-cmos.c
@@ -649,11 +649,10 @@ static struct cmos_rtc	cmos_rtc;
 
 static irqreturn_t cmos_interrupt(int irq, void *p)
 {
-	unsigned long	flags;
 	u8		irqstat;
 	u8		rtc_control;
 
-	spin_lock_irqsave(&rtc_lock, flags);
+	spin_lock(&rtc_lock);
 
 	/* When the HPET interrupt handler calls us, the interrupt
 	 * status is passed as arg1 instead of the irq number.  But
@@ -687,7 +686,7 @@ static irqreturn_t cmos_interrupt(int irq, void *p)
 			hpet_mask_rtc_irq_bit(RTC_AIE);
 		CMOS_READ(RTC_INTR_FLAGS);
 	}
-	spin_unlock_irqrestore(&rtc_lock, flags);
+	spin_unlock(&rtc_lock);
 
 	if (is_intr(irqstat)) {
 		rtc_update_irq(p, 1, irqstat);
-- 
2.8.1

[PATCH 2/6] rtc: pm8xxx: Replace spin_lock_irqsave with spin_lock in hard IRQ

[Xiaofei Tan]

It is redundant to do irqsave and irqrestore in hardIRQ context, where
it has been in a irq-disabled context.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
---
 drivers/rtc/rtc-pm8xxx.c | 9 ++++-----
 1 file changed, 4 insertions(+), 5 deletions(-)

diff --git a/drivers/rtc/rtc-pm8xxx.c b/drivers/rtc/rtc-pm8xxx.c
index 0d9dd6f..92642aa 100644
--- a/drivers/rtc/rtc-pm8xxx.c
+++ b/drivers/rtc/rtc-pm8xxx.c
@@ -343,16 +343,15 @@ static irqreturn_t pm8xxx_alarm_trigger(int irq, void *dev_id)
 	const struct pm8xxx_rtc_regs *regs = rtc_dd->regs;
 	unsigned int ctrl_reg;
 	int rc;
-	unsigned long irq_flags;
 
 	rtc_update_irq(rtc_dd->rtc, 1, RTC_IRQF | RTC_AF);
 
-	spin_lock_irqsave(&rtc_dd->ctrl_reg_lock, irq_flags);
+	spin_lock(&rtc_dd->ctrl_reg_lock);
 
 	/* Clear the alarm enable bit */
 	rc = regmap_read(rtc_dd->regmap, regs->alarm_ctrl, &ctrl_reg);
 	if (rc) {
-		spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
+		spin_unlock(&rtc_dd->ctrl_reg_lock);
 		goto rtc_alarm_handled;
 	}
 
@@ -360,13 +359,13 @@ static irqreturn_t pm8xxx_alarm_trigger(int irq, void *dev_id)
 
 	rc = regmap_write(rtc_dd->regmap, regs->alarm_ctrl, ctrl_reg);
 	if (rc) {
-		spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
+		spin_unlock(&rtc_dd->ctrl_reg_lock);
 		dev_err(rtc_dd->rtc_dev,
 			"Write to alarm control register failed\n");
 		goto rtc_alarm_handled;
 	}
 
-	spin_unlock_irqrestore(&rtc_dd->ctrl_reg_lock, irq_flags);
+	spin_unlock(&rtc_dd->ctrl_reg_lock);
 
 	/* Clear RTC alarm register */
 	rc = regmap_read(rtc_dd->regmap, regs->alarm_ctrl2, &ctrl_reg);
-- 
2.8.1

[PATCH 3/6] rtc: r7301: Replace spin_lock_irqsave with spin_lock in hard IRQ

[Xiaofei Tan]

It is redundant to do irqsave and irqrestore in hardIRQ context, where
it has been in a irq-disabled context.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
---
 drivers/rtc/rtc-r7301.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/rtc/rtc-r7301.c b/drivers/rtc/rtc-r7301.c
index aaf1b95..5dbaeb7 100644
--- a/drivers/rtc/rtc-r7301.c
+++ b/drivers/rtc/rtc-r7301.c
@@ -320,11 +320,10 @@ static irqreturn_t rtc7301_irq_handler(int irq, void *dev_id)
 {
 	struct rtc_device *rtc = dev_id;
 	struct rtc7301_priv *priv = dev_get_drvdata(rtc->dev.parent);
-	unsigned long flags;
 	irqreturn_t ret = IRQ_NONE;
 	u8 alrm_ctrl;
 
-	spin_lock_irqsave(&priv->lock, flags);
+	spin_lock(&priv->lock);
 
 	rtc7301_select_bank(priv, 1);
 
@@ -335,7 +334,7 @@ static irqreturn_t rtc7301_irq_handler(int irq, void *dev_id)
 		rtc_update_irq(rtc, 1, RTC_IRQF | RTC_AF);
 	}
 
-	spin_unlock_irqrestore(&priv->lock, flags);
+	spin_unlock(&priv->lock);
 
 	return ret;
 }
-- 
2.8.1

[PATCH 4/6] rtc: tegra: Replace spin_lock_irqsave with spin_lock in hard IRQ

[Xiaofei Tan]

It is redundant to do irqsave and irqrestore in hardIRQ context, where
it has been in a irq-disabled context.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
---
 drivers/rtc/rtc-tegra.c | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/drivers/rtc/rtc-tegra.c b/drivers/rtc/rtc-tegra.c
index 8925015..85f7ad5 100644
--- a/drivers/rtc/rtc-tegra.c
+++ b/drivers/rtc/rtc-tegra.c
@@ -232,7 +232,7 @@ static irqreturn_t tegra_rtc_irq_handler(int irq, void *data)
 {
 	struct device *dev = data;
 	struct tegra_rtc_info *info = dev_get_drvdata(dev);
-	unsigned long events = 0, flags;
+	unsigned long events = 0;
 	u32 status;
 
 	status = readl(info->base + TEGRA_RTC_REG_INTR_STATUS);
@@ -240,10 +240,10 @@ static irqreturn_t tegra_rtc_irq_handler(int irq, void *data)
 		/* clear the interrupt masks and status on any IRQ */
 		tegra_rtc_wait_while_busy(dev);
 
-		spin_lock_irqsave(&info->lock, flags);
+		spin_lock(&info->lock);
 		writel(0, info->base + TEGRA_RTC_REG_INTR_MASK);
 		writel(status, info->base + TEGRA_RTC_REG_INTR_STATUS);
-		spin_unlock_irqrestore(&info->lock, flags);
+		spin_unlock(&info->lock);
 	}
 
 	/* check if alarm */
-- 
2.8.1

[PATCH 5/6] rtc: mxc: Replace spin_lock_irqsave with spin_lock in hard IRQ

[Xiaofei Tan]

It is redundant to do irqsave and irqrestore in hardIRQ context, where
it has been in a irq-disabled context.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
---
 drivers/rtc/rtc-mxc.c | 5 ++---
 1 file changed, 2 insertions(+), 3 deletions(-)

diff --git a/drivers/rtc/rtc-mxc.c b/drivers/rtc/rtc-mxc.c
index 65b29b0..db57dda7 100644
--- a/drivers/rtc/rtc-mxc.c
+++ b/drivers/rtc/rtc-mxc.c
@@ -189,11 +189,10 @@ static irqreturn_t mxc_rtc_interrupt(int irq, void *dev_id)
 	struct platform_device *pdev = dev_id;
 	struct rtc_plat_data *pdata = platform_get_drvdata(pdev);
 	void __iomem *ioaddr = pdata->ioaddr;
-	unsigned long flags;
 	u32 status;
 	u32 events = 0;
 
-	spin_lock_irqsave(&pdata->rtc->irq_lock, flags);
+	spin_lock(&pdata->rtc->irq_lock);
 	status = readw(ioaddr + RTC_RTCISR) & readw(ioaddr + RTC_RTCIENR);
 	/* clear interrupt sources */
 	writew(status, ioaddr + RTC_RTCISR);
@@ -209,7 +208,7 @@ static irqreturn_t mxc_rtc_interrupt(int irq, void *dev_id)
 		events |= (RTC_PF | RTC_IRQF);
 
 	rtc_update_irq(pdata->rtc, 1, events);
-	spin_unlock_irqrestore(&pdata->rtc->irq_lock, flags);
+	spin_unlock(&pdata->rtc->irq_lock);
 
 	return IRQ_HANDLED;
 }
-- 
2.8.1

[PATCH 6/6] rtc: mxc_v2: Replace spin_lock_irqsave with spin_lock in hard IRQ

[Xiaofei Tan]

It is redundant to do irqsave and irqrestore in hardIRQ context, where
it has been in a irq-disabled context.

Signed-off-by: Xiaofei Tan <tanxiaofei@huawei.com>
---
 drivers/rtc/rtc-mxc_v2.c | 7 +++----
 1 file changed, 3 insertions(+), 4 deletions(-)

diff --git a/drivers/rtc/rtc-mxc_v2.c b/drivers/rtc/rtc-mxc_v2.c
index 0d73f6f..a577a74 100644
--- a/drivers/rtc/rtc-mxc_v2.c
+++ b/drivers/rtc/rtc-mxc_v2.c
@@ -74,13 +74,12 @@ static irqreturn_t mxc_rtc_interrupt(int irq, void *dev_id)
 	struct device *dev = dev_id;
 	struct mxc_rtc_data *pdata = dev_get_drvdata(dev);
 	void __iomem *ioaddr = pdata->ioaddr;
-	unsigned long flags;
 	u32 lp_status;
 	u32 lp_cr;
 
-	spin_lock_irqsave(&pdata->lock, flags);
+	spin_lock(&pdata->lock);
 	if (clk_enable(pdata->clk)) {
-		spin_unlock_irqrestore(&pdata->lock, flags);
+		spin_unlock(&pdata->lock);
 		return IRQ_NONE;
 	}
 
@@ -104,7 +103,7 @@ static irqreturn_t mxc_rtc_interrupt(int irq, void *dev_id)
 
 	mxc_rtc_sync_lp_locked(dev, ioaddr);
 	clk_disable(pdata->clk);
-	spin_unlock_irqrestore(&pdata->lock, flags);
+	spin_unlock(&pdata->lock);
 	return IRQ_HANDLED;
 }
 
-- 
2.8.1

Re: [PATCH 0/6] spin lock usage optimization for RTC drivers

[Alexandre Belloni]

On Wed, 3 Feb 2021 20:39:35 +0800, Xiaofei Tan wrote:
> Replace spin_lock_irqsave with spin_lock in hard IRQ of RTC drivers.
> There is no function changes, but may speed up if interrupt happen
> too often.
> 
> Xiaofei Tan (6):
>   rtc: cmos: Replace spin_lock_irqsave with spin_lock in hard IRQ
>   rtc: pm8xxx: Replace spin_lock_irqsave with spin_lock in hard IRQ
>   rtc: r7301: Replace spin_lock_irqsave with spin_lock in hard IRQ
>   rtc: tegra: Replace spin_lock_irqsave with spin_lock in hard IRQ
>   rtc: mxc: Replace spin_lock_irqsave with spin_lock in hard IRQ
>   rtc: mxc_v2: Replace spin_lock_irqsave with spin_lock in hard IRQ
> 
> [...]

Applied, thanks!

[1/6] rtc: cmos: Replace spin_lock_irqsave with spin_lock in hard IRQ
      commit: 6950d046eb6eabbc271fda416460c05f7a85698a
[2/6] rtc: pm8xxx: Replace spin_lock_irqsave with spin_lock in hard IRQ
      commit: 51317975565329ee50e52d0fffce50566b43cc2d
[3/6] rtc: r7301: Replace spin_lock_irqsave with spin_lock in hard IRQ
      commit: be3df3f85897e36163bfb764549acc69ec9b7afa
[4/6] rtc: tegra: Replace spin_lock_irqsave with spin_lock in hard IRQ
      commit: 669022c29af672205aaf53b76fd594dad2661ffe
[5/6] rtc: mxc: Replace spin_lock_irqsave with spin_lock in hard IRQ
      commit: 3f2d30184773e408c4e6f9e15c350828e482480c
[6/6] rtc: mxc_v2: Replace spin_lock_irqsave with spin_lock in hard IRQ
      commit: 0c1095d334dafda22463454b0519c926447b555e

Best regards,
-- 
Alexandre Belloni <alexandre.belloni@bootlin.com>