Date: Fri, 29 Apr 2011 20:50:12 GMT From: Arnaud Lacombe <lacombar@gmail.com> To: freebsd-amd64@FreeBSD.org Subject: Re: amd64/156725: USB stack stall cause complete system input loss Message-ID: <201104292050.p3TKoCZE067541@freefall.freebsd.org>
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The following reply was made to PR amd64/156725; it has been noted by GNATS. From: Arnaud Lacombe <lacombar@gmail.com> To: bug-followup@FreeBSD.org, lacombar@gmail.com Cc: Subject: Re: amd64/156725: USB stack stall cause complete system input loss Date: Fri, 29 Apr 2011 16:48:52 -0400 this bug is tightly related to amd64/156726. Considering the following scenario: 1) plug a snd_uaudio(4)-based device 2) open aumix(1) on, pcmN, the mixer device attached to the previously attached device 3) unplug the snd_uaudio(4)-based device [the USB stack busy wait pcmN detach] 4) close aumix(1) [pcmN finally detach] If there is no USB activity (ie, no attach/detach, but "normal" hid activity), the USB stack recovers. If another USB device is attached/detached while the stack busy wait on pcmN detachment (between step 3 and step 4), events ends up being queued. Once step 4 is done, events gets processed, however, once completed the USB stall, ie. no more mouse or keyboard. At this point, I do not see any USB related message while the system halts.
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