Add a new interface get_pm_transition() to return pm_transition state. This interface is intended to be used from dev_pm_ops class and type suspend interfaces that call legacy pm ops driver suspend interfaces. Legacy suspend pm_ops take pm_message_t as a parameter.
e.g: drm_class_suspend() calls into driver suspend routines via drm_dev->driver->suspend(drm_dev, state).
Once drm_class_suspend() is converted to dev_pm_ops, it will no longer have access to pm_transition which it has to pass into driver legacy suspend calls. get_pm_transition() interface addresses this need.
Signed-off-by: Shuah Khan shuah.kh@samsung.com --- drivers/base/power/main.c | 17 +++++++++++++++++ include/linux/pm.h | 3 +++ 2 files changed, 20 insertions(+)
diff --git a/drivers/base/power/main.c b/drivers/base/power/main.c index c2132b8..3e2e09d 100644 --- a/drivers/base/power/main.c +++ b/drivers/base/power/main.c @@ -57,6 +57,23 @@ static pm_message_t pm_transition; static int async_error;
/** + * get_pm_transition - return pm_transition state. + * This interface is intended to be used from dev_pm_ops class and type + * suspend interfaces that call legacy pm ops driver suspend interfaces. + * Legacy suspend pm_ops take pm_message_t as a parameter. + * e.g: drm_class_suspend() calls into driver suspend routines + * via drm_dev->driver->suspend(drm_dev, state). + * Once drm_class_suspend() is converted to dev_pm_ops, it will no longer + * have access to pm_transition which it has to pass into driver legacy + * suspend calls. get_pm_transition() interface addresses this need. +*/ +pm_message_t get_pm_transition() +{ + return pm_transition; +} +EXPORT_SYMBOL_GPL(get_pm_transition); + +/** * device_pm_sleep_init - Initialize system suspend-related device fields. * @dev: Device object being initialized. */ diff --git a/include/linux/pm.h b/include/linux/pm.h index a224c7f..46f3252 100644 --- a/include/linux/pm.h +++ b/include/linux/pm.h @@ -63,6 +63,9 @@ typedef struct pm_message { int event; } pm_message_t;
+/* drivers/base/power/main.c */ +extern pm_message_t get_pm_transition(void); + /** * struct dev_pm_ops - device PM callbacks *
On 06/22/2013 03:17 PM, Rafael J. Wysocki wrote:
Yes that is correct that there is no need pass in or know pm_transition with dev_pm_ops. The issue I am running into is the legacy pm_ops class suspend/resume routines call. In the example, I mentioned in my changelog, drm_class_suspend() calls legacy pm_ops and passes in state. It passes in the state to the driver legacy suspend routine. I have seen code paths in drivers that differentiate between PM_EVENT_FREEZE, PM_EVENT_SUSPEND, PM_EVENT_SLEEP etc.
I considered passing PM_EVENT_SUSPEND to drm_dev->driver->suspend(drm_dev, state) from drm_class_suspend() which would eliminate the need for this new interface. However, I am concerned about breaking driver legacy suspend routines that key of off the state to execute different code paths for PM_EVENT_FREEZE vs. PM_EVENT_SUSPEND. Suspend routines get called when state is is PM_EVENT_FREEZE based on my testing.
I would rather not add a new interface. Hoping you will have another idea on how to pass in the state to legacy suspend/resume without adding this new interface. My thinking is that this new interface is temporary measure until all of the legacy suspend routines get converted to dev_pm_ops and at the tile legacy interface gets removed, this new interface can go away as well.
thanks, -- Shuah
Shuah Khan, Linux Kernel Developer - Open Source Group Samsung Research America (Silicon Valley) shuah.kh@samsung.com | (970) 672-0658
On Monday, June 24, 2013 04:20:06 PM Shuah Khan wrote:
There are multiple bus types with legacy callbacks. PCI and platform for two examples and USB does something similar. Please have a look at these.
Thanks, Rafael
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