On Fri, 23 Jul 2010, Raj Kumar wrote: > Hi, > > > I am implementing the run time power management in my drivers. So i have the following > questions: > > > 1) I am using the work queue approach for run time power management, Now the thing is > when the device is idle and it notifies the run time power management via helper function > pm_request_idle, and at the same time if resume is done then in that case does the runtime power management > cancels the idle and does not invoke any callback like runtime_suspend of driver? How can a resume occur while the device is idle? Idle means that the device isn't suspended -- it's at full power but not doing anything. Hence a resume cannot occur at the same time. > 2) like as mentioned in run time power management document, when the usage_count of device > reaches zero, is there any run time power management thread in background that will immediately suspends > the device or it is again via helper functions. It seems from the code that usage_count is zero and suspended > via helper functions. Is it correct? All suspends occur via the helper functions, whether a background thread is involved or not. > 3) The third question is more specific about platform bus usage? can the char device driver use platform bus? > can char device register as platform device? Yes. Devices can be registered on any bus. Alan Stern _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
