Messages in this thread | | | Date | Wed, 03 Apr 2019 17:52:20 +0200 | From | Paul Cercueil <> | Subject | Re: [PATCH] usb: musb: Force-disable pullup on shutdown |
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Le mer. 3 avril 2019 à 17:46, Bin Liu <b-liu@ti.com> a écrit : > On Wed, Apr 03, 2019 at 05:31:31PM +0200, Paul Cercueil wrote: >> >> >> Le mer. 3 avril 2019 à 15:26, Bin Liu <b-liu@ti.com> a écrit : >> >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@ti.com> 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@ti.com> 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. >> >> An important thing that I did not mention, is that the SoC boots >> from USB, >> so the pullup is active before the musb driver loads. Since in my >> case a > > It sounds to me that the musb driver should disable the pullup during > init. Isn't it?
Yes. I can move it to musb_gadget_setup(). Should I still protect it with the spinlock then?
>> configfs gadget is never bound, then .pullup() is never called, and >> when >> I unbind the driver the pullup is still enabled. > > Regards, > -Bin.
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