On Tue, 28 Nov 2017, Ladislav Michl wrote: > On Tue, Nov 28, 2017 at 10:00:32AM -0500, Alan Stern wrote: > > 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. > > Here's relevant part of bootlog: ... > > 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)? > > $ ls /sys/kernel/debug/usb > devices ohci > > So no ehci. ... > For ohci it is the same. Any hint why there's no ehco file? The EHCI debugging files require CONFIG_DYNAMIC_DEBUG to be enabled. Oddly enough, the OHCI debugging files do not have the same requirement. I don't know the reason for this difference. Alan Stern -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
