From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ivaylo Dimitrov Subject: Re: USB gadgets with configfs hang reboot Date: Mon, 25 Apr 2016 22:00:19 +0300 Message-ID: <571E6943.30305@gmail.com> References: <20160115224839.GA19432@atomide.com> <569A1E32.1020502@gmail.com> <57081105.2050206@gmail.com> <87oa97gxkw.fsf@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <87oa97gxkw.fsf-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> Sender: linux-usb-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Felipe Balbi , Tony Lindgren Cc: linux-usb-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, linux-omap-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Greg Kroah-Hartman , Robert Baldyga , Andrzej Pietrasiewicz , Alan Stern , Michal Nazarewicz List-Id: linux-omap@vger.kernel.org Hi, On 18.04.2016 10:55, Felipe Balbi wrote: > > Hi, > > Ivaylo Dimitrov writes: >> Hi, >> >> On 16.01.2016 12:40, Ivaylo Dimitrov wrote: >>> Hi, >>> >>> On 16.01.2016 00:48, Tony Lindgren wrote: >>>> Hi all, >>>> >>>> Looks like there's some issue with the USB gadgets and configfs. >>>> >>>> I'm seeing rmmod of the UDC driver cause a warning and then reboot >>>> hangs the system. This happens at least with v4.4, and I've reproduced >>>> it with dwc3 and musb so it seems to be generic. >>>> >>> >>> Having configfs is not needed, disabling usb gadgets (# >>> CONFIG_USB_MUSB_GADGET is not set) seems to solved at least poweroff >>> hang issue on N900. Also, g_nokia is not a module in the config I use, >>> so I guess the problem is not related whether gadgets are modular or >>> not. Unfortunately I was not able to test reboot, as rootfs became >>> corrupted after the first poweroff :( . So it looks like my theory that >>> onenand corruption on N900 is because poweroff/reboot hangs is wrong. >> >> (copied from "Re: [PATCH] usb: f_mass_storage: test whether thread is >> running before starting another" thread) >> >> Yet another problem with USB gadget, this time with f_acm - if there is >> an open /dev/ttyGSn device, it is impossible to reboot/power down the >> device. >> >> My investigation shown that there is a process(pnatd) that opens >> /dev/ttyGSn devices, so gserial_free_port() hangs on >> wait_event(port->close_wait, gs_closed(port)); if I do "cd >> /sys/bus/platform/drivers/musb-hdrc && echo musb-hdrc.0.auto > unbind". >> >> Unfortunately I don't have serial debug port connector on my N900, so I >> can't capture logs after the reboot command, however, I suspect it hangs >> on the same place as with unbind. >> >> That looks weird, as one would expect that close() is called when the >> kernel kills user processes on reboot/powerdown. > > right, care to enable lockup detection and see if you can get more info > out of it ? > Nothing interesting, besides that screen does not work :(. However, the device boots, I can connect through wifi and reboot still hangs. Also, I don't see that port->close_wait in /proc/lockdep. Is that expected? Is there a reason why a process (pnatd in this particular case) doesn't get killed on reboot? Ivo -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html