Hi Zixun, On Fri, 26 Jul 2024 at 07:24, Zixun LI <ad...@hifiphile.com> wrote: > > Bind/unbind a gadget function driver to a USB gadget device doesn't work > with class index, while using node path is ok. For example: > > U-Boot> dm tree > > Class Index Probed Driver Name > ----------------------------------------------------------- > root 0 [ + ] root_driver root_driver > simple_bus 0 [ + ] simple_bus |-- ahb > simple_bus 1 [ + ] simple_bus | |-- apb > ... > usb 0 [ ] atmel_usba_udc | | |-- gadget@f803c000 > > U-Boot> bind usb 0 usb_ether > Cannot find device 0 of class usb > > Both USB host uclass and USB gadget uclass are using the same name "usb" > while they are under different class id of UCLASS_USB and > UCLASS_USB_GADGET_GENERIC. > > bind_by_class_index() of cmd/bind.c uses uclass_get_by_name() to find > class id, since both class have the same name it will get the id of > UCLASS_USB instead since it is at the front of the uclass id list. > > Then uclass_find_device() will try to find the wrong device and fail. > > But fixing this issue simply by renaming gadget uclass name will break > the DT alias feature DM_UC_FLAG_SEQ_ALIAS. > > Any idea how to fix it ? Like adding a name_seq_alias field to > uclass_driver structure ?
It looks like test/py/tests/test_bind.py does not cover this case. We don't have a check for duplicate uclass names but probably should. Also sandbox builds USB gadget support but I don't think it is used. If it were we could add a test for this case. I think the UDC uclass should be renamed to "usb_gadget". That may end up requiring changes elsewhere, but I'm not sure. There are also weird things like omap2430_musb having two different uclass IDs! Regards, SImon
