Patch "pinctrl: cherryview: Serialize register access in suspend/resume" has been added to the 4.8-stable tree

This is a note to let you know that I've just added the patch titled

pinctrl: cherryview: Serialize register access in suspend/resume

to the 4.8-stable tree which can be found at:
http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary

The filename of the patch is:
pinctrl-cherryview-serialize-register-access-in-suspend-resume.patch
and it can be found in the queue-4.8 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree, please let <[email protected]> know about it.

From: Mika Westerberg <[email protected]>
Date: Mon, 31 Oct 2016 16:57:32 +0200
Subject: pinctrl: cherryview: Serialize register access in suspend/resume

From: Mika Westerberg <[email protected]>

commit 56211121c0825cd188caad05574fdc518d5cac6f upstream.

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.

---
 drivers/pinctrl/intel/pinctrl-cherryview.c |   10 ++++++++++
 1 file changed, 10 insertions(+)

@@ -1638,8 +1638,11 @@ static int chv_pinctrl_suspend(struct de
 {
 	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++) {

@@ -1660,6 +1663,8 @@ static int chv_pinctrl_suspend(struct de
 		ctx->padctrl1 = readl(reg);
 	}
 
+	raw_spin_unlock_irqrestore(&chv_lock, flags);
+
 	return 0;
 }
 

@@ -1667,8 +1672,11 @@ static int chv_pinctrl_resume(struct 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

@@ -1713,6 +1721,8 @@ static int chv_pinctrl_resume(struct 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

Patches currently in stable-queue which might be from [email protected] are

queue-4.8/pinctrl-cherryview-prevent-possible-interrupt-storm-on-resume.patch queue-4.8/pinctrl-cherryview-serialize-register-access-in-suspend-resume.patch