Petr Cvek <petr.cvek@xxxxxx> writes: > Dne 12.2.2017 v 13:02 Robert Jarzmik napsal(a): > That's weird I even removed pxa_set_udc_info() from magician machine init and it still fails. > Host cable and/or actual camera is not required. It fails without them. > > So you binded pxa27x-udc as UDC controller (= activated it) and then rmmoded > it and nobody complained? No, that usecase actually fails. I think you could submit a proper patch with the diff in [1], with which the pxa27x-udc unloading will work. But it's not _your_ testcase, as per your provided callstack : [ 2152.826529] [<bf4a1914>] (udc_bind_to_driver [udc_core]) from [<bf4a1b08>] (usb_add_gadget_udc_release+0x138/0x21c [udc_core]) [ 2152.826731] [<bf4a1b08>] (usb_add_gadget_udc_release [udc_core]) from [<bf4db838>] (pxa_udc_probe+0x290/0x2fc [pxa27x_udc]) [ 2152.833554] [<bf4db838>] (pxa_udc_probe [pxa27x_udc]) from [<c02522d0>] (platform_drv_probe+0x38/0x84) [ 2152.833602] [<c02522d0>] (platform_drv_probe) from [<c0250784>] (driver_probe_device+0x1e0/0x3f4) Your problem seems in the pxa_udc_probe(), which I would presume you're doing for a second time, ie. after modprobe pxa27x_udc + bind UDC controller + rmmod pxa27x_udc + modprobe pxa27x_udc. I suspect that in this case, the problem is that the rmmod works while udc is still bound to the composite. The lsmod seems to prove that the refcount is still 0 while usb_f_uvc is is bound to pxa27x_udc. [@Felipe and @Laurent] I have no knowledge of usb_f_uvc, so would you tell me if binding usb_f_uvc to pxa27_udc should have incremented the module refcount of pxa27x_udc or not ? > Can you try v4.10? Or send me exact commit on what you tested it so I can test > it too. My top commit (not counting yours) is : 61c04572de40 ("Merge branch 'for-rc' of git://git.kernel.org/pub/scm/linux/kernel/git/rzhang/linux") Cheers. -- Robert [1] diff --git a/drivers/usb/gadget/udc/pxa27x_udc.c b/drivers/usb/gadget/udc/pxa27x_udc.c index 9fb103348b5d..a239eb836652 100644 --- a/drivers/usb/gadget/udc/pxa27x_udc.c +++ b/drivers/usb/gadget/udc/pxa27x_udc.c @@ -2512,7 +2512,8 @@ static int pxa_udc_remove(struct platform_device *_dev) usb_del_gadget_udc(&udc->gadget); pxa_cleanup_debugfs(udc); - usb_put_phy(udc->transceiver); + if (!IS_ERR(udc->transceiver)) + usb_put_phy(udc->transceiver); udc->transceiver = NULL; the_controller = NULL; -- 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