> > > > > > > > > > > > > > > In your case, you should not set CONFIG_USB_OTG no matter at > > > > defconfig and at menuconfig. > > > > > > Hmm, at least in my testing (USB mouse/keyboard connected to OTG > > > port), it works as before even I enable CONFIG_USB_OTG, as long as I > > > do *not* enable CONFIG_USB_OTG_FSM. > > > > > > Since it works for my case, I'm wondering why you think I shouldn't > > > enable CONFIG_USB_OTG at all. > > > > > > > If your device is not OTG device, there is no reason you need to > > enable CONFIG_USB_OTG. > > Whether I should enable CONFIG_USB_OTG depends on what devices I will use? > This is insane to me. > Sorry, here, your device = your board > Look, there is an USB OTG port on my board, and it should just be the > reason that's good enough for me to build a kernel with CONFIG_USB_OTG, > shouldn't it? I do not even know what type of devices will be plugged > into this USB OTG port when I was building the kernel. > There is NO term for "OTG port" at USB spec, it only has a term of "OTG device", which means " Device that provides both host and peripheral capabilities over a single Micro-AB receptacle". If your device is an "OTG device", and supports role switch without disconnect your usb cable (HNP), you should set CONFIG_USB_OTG. Taking imx6 sabreSD board as an example, it is a Micro-B port. >From what kinds of port (A or B), we don't know which capabilities your device has, with different cables, you will get different functions. Currently, the capabilities are decided by: controller capabilities (otg, host/device-only, etc) and can be override by dts due to board design. otg has special protocol and TPL requirements, it is decided by kernel configuration. The Kconfig description for USB_OTG is not very accurate, it should mention the HNP and SRP supported are needed for that config, not just dual-role switch through ID pin, I will submit a patch for that Peter > Shawn > > > Yes, it may work for some devices when enable CONFIG_USB_OTG, but it > > will confuse other host or device which is connected with you, eg, > > your device will report your have supported some otg capabilities, eg, > > SRP or HNP. -- 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
