On Tue, 28 Nov 2017, Greg KH wrote: > On Mon, Nov 27, 2017 at 11:08:33PM +0100, Ladislav Michl wrote: > > Hi there, > > > > USB hosts do not discover any connected device on OMAP3 based board > > with CONFIG_PM=n. Just enabling this option is enough to restore working > > behaviour. Nothing unusual in log. Tested 4.14.2 and 4.15-rc1. I know > > a lot of stuff depends on CONFIG_PM, but is this expected behaviour? > > Neither EHCI nor MUSB is working without CONFIG_PM. > > What bus type is your controllers on? PCI? platform? Something else? > > And yes, perhaps this is to be expected, why would you not want > CONFIG_PM to be enabled? :) Well, no, it's not expected. Systems are supposed to work correctly with CONFIG_PM=n -- just not at an optimum power level. EHCI certainly should work without CONFIG_PM. When a device is plugged in to the EHCI controller, what shows up in /sys/kernel/debug/usb/ehci/*/registers (fill in the '*' with the correct bus ID)? For that matter, what does that file contain before any devices are plugged in? Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
