hi PM_RUNTIME provide a way for device driver do runtime PM. so for some devices, they have some surrounded logic. For example, the device may get clock from outside, or it need PHY support(USB is a example). To get these dependency out of device driver, i define a struct dev_pm_domain, and make dev.pm_domain point to it. So in the device driver, when the hardware should be enabled, we can call pm_runtime_get_sync while when the hardware is idle or does not work, we can call pm_runtime_put_sync. It seems work well, but i have question about the suspend/resume of device. When the whole system will go to deep idle, and it will suspend the devices. for the function do device suspend __device_suspend, it will call pm_runtime_get_noresume(dev). As i think it will make the device not do runtime suspend any more. Is that correct? There is the question, how device driver handle the logic surrounds it? I want to add pm_runtime_put_sync in dev->driver->pm->suspend function, and pm_runtime_get_sync in dev->driver->pm->resume. Because __device_suspend increase the usage_count, pm_runtime_put_sync will not do real work. So is that right that i directly call pm_runtime_suspend in dev->driver->pm->suspend and pm_runtime_resume in dev->driver->pm->resume? Thanks.
