On Mon, Jul 22, 2019 at 01:56:45PM +0200, Pavel Machek wrote: > Hi! > > > > >> This patch introduce new Cadence USBSS DRD driver to linux kernel. > > > >> > > > >> The Cadence USBSS DRD Controller is a highly configurable IP Core which > > > >> can be instantiated as Dual-Role Device (DRD), Peripheral Only and > > > >> Host Only (XHCI)configurations. > > > > > > > >I see you are using debugfs to select between DRD, peripheral-onlyh and XHCI... > > > > > > > >Is that good idea? > > > > > > Yes driver allows selecting dr_mode by debugfs. Controller also support such functionality > > > so I don't understand why would it not be a good idea. > > > > > > I personally use this for testing but it can be used to limit controller functionality without > > > recompiling kernel. > > > > debugfs is ONLY for debugging, never rely on it being enabled, or > > mounted, on a system in order to have any normal operation happen. > > > > So for testing, yes, this is fine. If this is going to be the normal > > api/interface for how to control this driver, no, that is not acceptable > > at all. > > It makes a lot of sense for end-user to toggle this... for example > when he is lacking right cable for proper otg detection. As it is > third driver offering this functionality, I believe we should stop > treating it as debugging. Then it needs to get out of debugfs, as again, that can not be used for any normal end-user operation. thanks, greg k-h
