On Monday, June 24, 2013 04:20:06 PM Shuah Khan wrote: > On 06/22/2013 03:17 PM, Rafael J. Wysocki wrote: > > On Saturday, June 22, 2013 02:11:14 PM Shuah Khan wrote: > >> 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. > > > > That shouldn't be necessary because each transition has its own callback > > in strict dev_pm_ops. > > > > Thanks, > > Rafael > > > > 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. 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 -- I speak only for myself. Rafael J. Wysocki, Intel Open Source Technology Center. _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
