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[PATCH 1/3] pinctrl: cherryview: Serialize register access in suspend and resume hooks

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If async suspend is enabled, the driver may access registers concurrently
with another instance which may fail because of the bug in Cherryview GPIO
hardware. Prevent this by taking the shared lock while accessing the
hardware in suspend and resume hooks.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
---
 drivers/pinctrl/intel/pinctrl-cherryview.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/pinctrl/intel/pinctrl-cherryview.c b/drivers/pinctrl/intel/pinctrl-cherryview.c
index 30389f4ccab4..097d835b3a50 100644
--- a/drivers/pinctrl/intel/pinctrl-cherryview.c
+++ b/drivers/pinctrl/intel/pinctrl-cherryview.c
@@ -1656,8 +1656,11 @@ static int chv_pinctrl_suspend(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct chv_pinctrl *pctrl = platform_get_drvdata(pdev);
+	unsigned long flags;
 	int i;
 
+	raw_spin_lock_irqsave(&chv_lock, flags);
+
 	pctrl->saved_intmask = readl(pctrl->regs + CHV_INTMASK);
 
 	for (i = 0; i < pctrl->community->npins; i++) {
@@ -1678,6 +1681,8 @@ static int chv_pinctrl_suspend(struct device *dev)
 		ctx->padctrl1 = readl(reg);
 	}
 
+	raw_spin_unlock_irqrestore(&chv_lock, flags);
+
 	return 0;
 }
 
@@ -1685,8 +1690,11 @@ static int chv_pinctrl_resume(struct device *dev)
 {
 	struct platform_device *pdev = to_platform_device(dev);
 	struct chv_pinctrl *pctrl = platform_get_drvdata(pdev);
+	unsigned long flags;
 	int i;
 
+	raw_spin_lock_irqsave(&chv_lock, flags);
+
 	/*
 	 * Mask all interrupts before restoring per-pin configuration
 	 * registers because we don't know in which state BIOS left them
@@ -1731,6 +1739,8 @@ static int chv_pinctrl_resume(struct device *dev)
 	chv_writel(0xffff, pctrl->regs + CHV_INTSTAT);
 	chv_writel(pctrl->saved_intmask, pctrl->regs + CHV_INTMASK);
 
+	raw_spin_unlock_irqrestore(&chv_lock, flags);
+
 	return 0;
 }
 #endif
-- 
2.9.3

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[PATCH 1/3] pinctrl: cherryview: Serialize register access in suspend and resume hooks Mika Westerberg <mika.westerberg@linux.intel.com> - 2016-10-31 16:00 +0100
  [PATCH 3/3] pinctrl: cherryview: Drop ctrlX prefix from the pin debugfs output Mika Westerberg <mika.westerberg@linux.intel.com> - 2016-10-31 16:00 +0100
    Re: [PATCH 3/3] pinctrl: cherryview: Drop ctrlX prefix from the pin  debugfs output Linus Walleij <linus.walleij@linaro.org> - 2016-11-04 16:20 +0100
  [PATCH 2/3] pinctrl: cherryview: Prevent possible interrupt storm on resume Mika Westerberg <mika.westerberg@linux.intel.com> - 2016-10-31 16:00 +0100
    Re: [PATCH 2/3] pinctrl: cherryview: Prevent possible interrupt storm  on resume Linus Walleij <linus.walleij@linaro.org> - 2016-11-04 16:20 +0100
  Re: [PATCH 1/3] pinctrl: cherryview: Serialize register access in  suspend and resume hooks Linus Walleij <linus.walleij@linaro.org> - 2016-11-04 16:20 +0100
    Re: [PATCH 1/3] pinctrl: cherryview: Serialize register access in  suspend and resume hooks Linus Walleij <linus.walleij@linaro.org> - 2016-11-04 16:20 +0100
      Re: [PATCH 1/3] pinctrl: cherryview: Serialize register access in  suspend and resume hooks Mika Westerberg <mika.westerberg@linux.intel.com> - 2016-11-04 16:40 +0100

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