Commit 084609bf authored Apr 24, 2015 by Grygorii Strashko Committed by Rafael J. Wysocki May 12, 2015

leds / PM: fix hibernation on arm when gpio-led used with CPU led trigger



Setting a dev_pm_ops suspend/resume pair of callbacks but not a set of
hibernation callbacks means those pm functions will not be
called upon hibernation - that leads to system crash on ARM during
freezing if gpio-led is used in combination with CPU led trigger.
It may happen after freeze_noirq stage (GPIO is suspended)
and before syscore_suspend stage (CPU led trigger is suspended)
- usually when disable_nonboot_cpus() is called.

Log:
  PM: noirq freeze of devices complete after 1.425 msecs
  Disabling non-boot CPUs ...
    ^ system may crash or stuck here with message (TI AM572x)

  WARNING: CPU: 0 PID: 3100 at drivers/bus/omap_l3_noc.c:148 l3_interrupt_handler+0x22c/0x370()
  44000000.ocp:L3 Custom Error: MASTER MPU TARGET L4_PER1_P3 (Idle): Data Access in Supervisor mode during Functional access

  CPU1: shutdown
    ^ or here

Fix this by using SIMPLE_DEV_PM_OPS, which appropriately
assigns the suspend and hibernation callbacks and move
led_suspend/led_resume under CONFIG_PM_SLEEP to avoid
build warnings.

Fixes: 73e1ab41 (leds: Convert led class driver from legacy pm ops to dev_pm_ops)
Signed-off-by: Grygorii Strashko <Grygorii.Strashko@linaro.org>
Acked-by: Jacek Anaszewski <j.anaszewski@samsung.com>
Cc: 3.11+ <stable@vger.kernel.org> # 3.11+
Signed-off-by: Rafael J. Wysocki <rafael.j.wysocki@intel.com>

parent c381f229

drivers/leds/led-class.c

+3 −4

Original line number	Diff line number	Diff line
		@@ -187,6 +187,7 @@ void led_classdev_resume(struct led_classdev *led_cdev)
		}
		EXPORT_SYMBOL_GPL(led_classdev_resume);

		#ifdef CONFIG_PM_SLEEP
		static int led_suspend(struct device *dev)
		{
		struct led_classdev *led_cdev = dev_get_drvdata(dev);
		@@ -206,11 +207,9 @@ static int led_resume(struct device *dev)

		return 0;
		}
		#endif

		static const struct dev_pm_ops leds_class_dev_pm_ops = {
		.suspend = led_suspend,
		.resume = led_resume,
		};
		static SIMPLE_DEV_PM_OPS(leds_class_dev_pm_ops, led_suspend, led_resume);

		static int match_name(struct device dev, const void data)
		{

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