On Fri, Nov 14, 2014 at 09:06:47AM -0600, Felipe Balbi wrote: > On Fri, Nov 14, 2014 at 03:33:44PM +0800, Peter Chen wrote: > > On Thu, Nov 13, 2014 at 09:55:34PM -0600, Felipe Balbi wrote: > > > Hi, > > > > > > On Fri, Nov 14, 2014 at 08:03:15AM +0800, Peter Chen wrote: > > > > Add controller reset API, it may be used for host/otg driver in future. > > > > > > you need a better commit log here. How would it be used ? when ? And, > > > more importantly, why ? > > > > > > > I will add more information > > > > > Why would we need to reset the IP outside of ->probe() ? > > > > > > I don't oppose to the refactoring, but why would we ever need to reset > > > this IP ? > > > > Usually, we need to below reset controller at below situations: > > - Role switch, host->device and device->host > > - Return from hibernation, which the controller will lost its power, > > and the content of the register are lost. > > resetting is probably not the best solution in either case, though. It > might be the easiest, but not the best. For suspend/resume, you would be > better off saving/restoring contenxt and for role switch, you could just > reprogram the few registers which need to change when role swapping. >
For safe reason, it is better to do reset controller at above two situations. Why we need to do reset at probe, it may also work if we program register directly. -- Best Regards, Peter Chen -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
