Patch "pinctrl: cherryview: Serialize register access in suspend/resume" has been added to the 4.4-stable tree

Patch "pinctrl: cherryview: Serialize register access in suspend/resume" has been added to the 4.4-stable tree

[gregkh]

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 4.4-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-4.4 subdirectory.

If you, or anyone else, feels it should not be added to the stable tree,
please let <stable@vger.kernel.org> know about it.


>From 56211121c0825cd188caad05574fdc518d5cac6f Mon Sep 17 00:00:00 2001
From: Mika Westerberg <mika.westerberg@linux.intel.com>
Date: Mon, 31 Oct 2016 16:57:32 +0200
Subject: pinctrl: cherryview: Serialize register access in suspend/resume

From: Mika Westerberg <mika.westerberg@linux.intel.com>

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.

Signed-off-by: Mika Westerberg <mika.westerberg@linux.intel.com>
Signed-off-by: Linus Walleij <linus.walleij@linaro.org>
Signed-off-by: Greg Kroah-Hartman <gregkh@linuxfoundation.org>

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

--- a/drivers/pinctrl/intel/pinctrl-cherryview.c
+++ b/drivers/pinctrl/intel/pinctrl-cherryview.c
@@ -1568,8 +1568,11 @@ 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++) {
@@ -1590,6 +1593,8 @@ static int chv_pinctrl_suspend(struct de
 		ctx->padctrl1 = readl(reg);
 	}
 
+	raw_spin_unlock_irqrestore(&chv_lock, flags);
+
 	return 0;
 }
 
@@ -1597,8 +1602,11 @@ 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
@@ -1643,6 +1651,8 @@ 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 mika.westerberg@linux.intel.com are

queue-4.4/pinctrl-cherryview-prevent-possible-interrupt-storm-on-resume.patch
queue-4.4/pinctrl-cherryview-serialize-register-access-in-suspend-resume.patch