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

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [thread-next>] [day] [month] [year] [list]

Date:	Wed, 10 Apr 2013 20:39:09 +0800
From:	Chuansheng Liu <chuansheng.liu@...el.com>
To:	broonie@...nsource.wolfsonmicro.com, sameo@...ux.intel.com
Cc:	linux-kernel@...r.kernel.org, patches@...nsource.wolfsonmicro.com,
	chuansheng.liu@...el.com
Subject: mfd, arizona: Fix the deadlock between interrupt handler and
 dpm_suspend


When system try to do the suspend:
T1:suspend_thread                         T2: interrupt thread handler
enter_state()                             arizona_irq_thread()
 suspend_devices_and_enter()                regmap_read()
  __device_suspend()
                                              regmap_spi_read()
                                               spi_write_then_read()
                                                spi_sync()
                                                 __spi_sync()
                                                  wait_for_completion()
                                          T2 <== Blocked here due to spi suspended
 suspend_enter()
  dpm_suspend_end()
   dpm_suspend_noirq()
    suspend_device_irqs()
     synchronize_irq()
T1 <== Blocked here due waiting for T2 finished

Then T1 and T2 is deadlocked there.

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.

Signed-off-by: liu chuansheng <chuansheng.liu@...el.com>
---
 drivers/mfd/arizona-core.c |   11 ++++-------
 1 files changed, 4 insertions(+), 7 deletions(-)

diff --git a/drivers/mfd/arizona-core.c b/drivers/mfd/arizona-core.c
index b562c7b..b11bd01 100644
--- a/drivers/mfd/arizona-core.c
+++ b/drivers/mfd/arizona-core.c
@@ -264,11 +264,11 @@ static int arizona_runtime_suspend(struct device *dev)
 #endif
 
 #ifdef CONFIG_PM_SLEEP
-static int arizona_resume_noirq(struct device *dev)
+static int arizona_suspend(struct device *dev)
 {
 	struct arizona *arizona = dev_get_drvdata(dev);
 
-	dev_dbg(arizona->dev, "Early resume, disabling IRQ\n");
+	dev_dbg(arizona->dev, "Suspend, disabling IRQ\n");
 	disable_irq(arizona->irq);
 
 	return 0;
@@ -278,7 +278,7 @@ static int arizona_resume(struct device *dev)
 {
 	struct arizona *arizona = dev_get_drvdata(dev);
 
-	dev_dbg(arizona->dev, "Late resume, reenabling IRQ\n");
+	dev_dbg(arizona->dev, "Resume, reenabling IRQ\n");
 	enable_irq(arizona->irq);
 
 	return 0;
@@ -289,10 +289,7 @@ 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)
-#ifdef CONFIG_PM_SLEEP
-	.resume_noirq = arizona_resume_noirq,
-#endif
+	SET_SYSTEM_SLEEP_PM_OPS(arizona_suspend, arizona_resume)
 };
 EXPORT_SYMBOL_GPL(arizona_pm_ops);
 
-- 
1.7.0.4



--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/