Hi, On Fri, 2019-03-15 at 11:26 +0200, Heikki Krogerus wrote: > Hi Chunfeng, > > On Fri, Mar 15, 2019 at 05:13:24PM +0800, Chunfeng Yun wrote: > > I encounter a build error when CONFIG_USB_ROLE_SWITCH is not enabled, > > > > drivers/usb/mtu3/mtu3_dr.o: In function `ssusb_role_sw_register': > > ./drivers/usb/mtu3/mtu3_dr.c:460: undefined reference to > > `usb_role_switch_register' > > drivers/usb/mtu3/mtu3_dr.o: In function `ssusb_otg_switch_exit': > > ./drivers/usb/mtu3/mtu3_dr.c:491: undefined reference to > > `usb_role_switch_unregister' > > So you need to add dependency on USB_ROLE_SWITCH, right? Yes > > --- a/drivers/usb/mtu3/Kconfig > +++ b/drivers/usb/mtu3/Kconfig > @@ -43,6 +43,7 @@ config USB_MTU3_DUAL_ROLE > bool "Dual Role mode" > depends on ((USB=y || USB=USB_MTU3) && (USB_GADGET=y || USB_GADGET=USB_MTU3)) > depends on (EXTCON=y || EXTCON=USB_MTU3) > + depends on USB_ROLE_SWITCH > help > This is the default mode of working of MTU3 controller where > both host and gadget features are enabled. > > > the following patch has fixed the issue, but seems not get into kernel, > > [v3,08/12] usb: roles: Add usb role switch notifier. > > https://patchwork.kernel.org/patch/10836525/ > > I don't understand how that fixes the problem? That patch will in any > case be targeting v5.2. We are in the middle of merge window, so > nothing is happening until v5.1-rc1 is tagged. It provides some dummy inline functions when USB_ROLE_SWITCH is not enabled, this will avoid build error > > > thanks, >
