On Thursday 09 July 2009, Mahalingam, Nithish wrote: > Hi, Hi, > I am newbee to this mailing list. Please excuse me if I am talking nonsense here. > > > > On Thu, Jul 9, 2009 at 10:48 PM, Alan Stern<stern@xxxxxxxxxxxxxxxxxxx> wrote: > >> On Thu, 9 Jul 2009, Magnus Damm wrote: > >> > >>> Clocks should be stopped as soon as possible without any delay. The > >>> clock stopping is very cheap performance wise. Also, the clock > >> stopping is done on bus level without invoking any driver callbacks. > >>> Delaying the clock stopping does not make any sense to me. > >> > >> In that case the device driver or bus subsystem should manage the > >> device's clock directly. There's no need to tie it in with the runtime > >> PM framework. Simply start the clock before each I/O operation and > >> stop it afterward. > > > It's not that easy. The clock needs to be enabled to let the hardware > > device perform device specific stuff. For instance, the clock for the > > LCD controller needs to be on to redraw the screen. When the driver > > knows that it's done with the clock it can notify the bus using > > Runtime PM. > > Is there any plan to look into the "Clock Framework" that was developed as > part of OMAP and extending this to make it generic for all platforms? I don't have any plan to do that and I heaven't heard of anyone planning to do it. Best, Rafael _______________________________________________ linux-pm mailing list linux-pm@xxxxxxxxxxxxxxxxxxxxxxxxxx https://lists.linux-foundation.org/mailman/listinfo/linux-pm
