On Tue, Apr 02, 2019 at 09:58:42PM +0200, Paul Cercueil wrote: > Hi, > > Le lun. 1 avril 2019 à 20:20, Bin Liu <b-liu@xxxxxx> a écrit : > >On Mon, Apr 01, 2019 at 07:46:22PM +0200, Paul Cercueil wrote: > >> > >> > >> Le lun. 1 avril 2019 à 19:17, Bin Liu <b-liu@xxxxxx> a écrit : > >> >On Thu, Mar 21, 2019 at 03:42:46PM +0100, Paul Cercueil wrote: > >> >> When the musb is shutdown, for instance when the driver is > >>unloaded, > >> >> force-disable the pullup. Otherwise, the host will still see > >> >>the gadget > >> >> device even after the shutdown. > >> > > >> >how would this happen? > >> > > >> >when musb-hdrc driver is unloaded, udc core removes the bound > >>gadget > >> >driver which calls musb_gadget_pullup() to disable the pullup. > >> > >> I'm testing with the jz4740-musb driver. I don't unload the > >>module (it's > >> built-in) but unbind it from sysfs. > > > >I did unbind too. > > > >root@am335x-evm:/sys/bus/platform/drivers/musb-hdrc# echo > >musb-hdrc.0 > unbind > > > >or unbind the glue driver: > > > >root@am335x-evm:/sys/bus/platform/drivers/musb-dsps# echo > >47401400.usb > unbind > > > >musb_gadget_pullup() is called in both cases. > > > >[ 3880.597014] [<bf444ab0>] (musb_gadget_pullup [musb_hdrc]) from > >[<bf402cbc>] (usb_gadget_disconnect+0x3c/0xf4 [udc_core]) > >[ 3880.607959] [<bf402cbc>] (usb_gadget_disconnect [udc_core]) > >from [<bf403b28>] (usb_gadget_remove_driver+0x4c/0x90 [udc_core]) > >[ 3880.619338] [<bf403b28>] (usb_gadget_remove_driver [udc_core]) > >from [<bf403d20>] (usb_del_gadget_udc+0x5c/0xc0 [udc_core]) > > In my case this stops here, usb_del_gadget_udc() does not call > usb_gadget_remove_driver(), that's why the pullup is never disabled. > > I guess that's because udc->driver is NULL; I'm testing with then the pullup should be disable by now. > CONFIG_USB_CONFIGFS, > and I don't configure anything in sysfs before unbinding the driver. I didn't check on this, but I could imagine that - when a configfs gadget is bound to the udc, .pullup() is called; - when the configfs gadget is unbound from the udc, .pullup should be called again to disable the pullup. -Bin.
