linux-kernel - Re: mfd, arizona: Fix the deadlock between interrupt handler and dpm

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Message-ID: <20130410123003.GZ9243@opensource.wolfsonmicro.com>
Date:	Wed, 10 Apr 2013 13:30:03 +0100
From:	Mark Brown <broonie@...nsource.wolfsonmicro.com>
To:	Chuansheng Liu <chuansheng.liu@...el.com>
Cc:	sameo@...ux.intel.com, linux-kernel@...r.kernel.org,
	patches@...nsource.wolfsonmicro.com
Subject: Re: mfd, arizona: Fix the deadlock between interrupt handler and
 dpm_suspend

On Wed, Apr 10, 2013 at 08:39:09PM +0800, Chuansheng Liu wrote:

> Here the arizona irq is not NOSUSPEND irq, so when doing device suspend,
> we can disable the arizona irq, and enable it until devices resuming finished.

Hrm, well - actually the primary IRQ probably ought to be a nosuspend in
the first place so this probably isn't what we want.  Something like the
below which does a similar thing to what we do on resume might help
here...  needs testing though.

From 538e817db94dc0c689ecfea7151b1a3f86bb204a Mon Sep 17 00:00:00 2001
From: Mark Brown <broonie@...nsource.wolfsonmicro.com>
Date: Wed, 10 Apr 2013 12:40:26 +0100
Subject: [PATCH] mfd: arizona: Disable interrupts during suspend

We aren't able to handle interrupts after the device has suspended since
we need to runtime resume it in order to do so but the controller may not
be available any more. Handle this in the same way as we handle a similar
issue on resume.

Reported-by: Chuansheng Liu <chuansheng.liu@...el.com>
Signed-off-by: Mark Brown <broonie@...nsource.wolfsonmicro.com>
---
 drivers/mfd/arizona-core.c |   23 ++++++++++++++++++++++-
 1 file changed, 22 insertions(+), 1 deletion(-)

diff --git a/drivers/mfd/arizona-core.c b/drivers/mfd/arizona-core.c
index 98023d8..c6be1f6 100644
--- a/drivers/mfd/arizona-core.c
+++ b/drivers/mfd/arizona-core.c
@@ -399,6 +399,26 @@ static int arizona_runtime_suspend(struct device *dev)
 #endif
 
 #ifdef CONFIG_PM_SLEEP
+static int arizona_suspend(struct device *dev)
+{
+	struct arizona *arizona = dev_get_drvdata(dev);
+
+	dev_dbg(arizona->dev, "Suspend, disabling IRQ\n");
+	disable_irq(arizona->irq);
+
+	return 0;
+}
+
+static int arizona_suspend_late(struct device *dev)
+{
+	struct arizona *arizona = dev_get_drvdata(dev);
+
+	dev_dbg(arizona->dev, "Late suspend, reenabling IRQ\n");
+	enable_irq(arizona->irq);
+
+	return 0;
+}
+
 static int arizona_resume_noirq(struct device *dev)
 {
 	struct arizona *arizona = dev_get_drvdata(dev);
@@ -424,8 +444,9 @@ const struct dev_pm_ops arizona_pm_ops = {
 	SET_RUNTIME_PM_OPS(arizona_runtime_suspend,
 			   arizona_runtime_resume,
 			   NULL)
-	SET_SYSTEM_SLEEP_PM_OPS(NULL, arizona_resume)
+	SET_SYSTEM_SLEEP_PM_OPS(arizona_suspend, arizona_resume)
 #ifdef CONFIG_PM_SLEEP
+	.suspend_late = arizona_suspend_late,
 	.resume_noirq = arizona_resume_noirq,
 #endif
 };
-- 
1.7.10.4


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