Messages in this thread Patch in this message | | | Date | Thu, 08 Apr 2010 14:22:36 +0200 | From | Takashi Iwai <> | Subject | Re: Ooops when working with USB MIDI (2.6.33.1) |
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At Thu, 08 Apr 2010 12:00:11 +0200, Clemens Ladisch wrote: > > Tvrtko Ursulin wrote: > > I had TuxGuitar running and an external USB MIDI device, which I then > > turned off, on, and exited TuxGuitar at which point there was this oops. > > ... > > [321182.618342] IP: [<ffffffff81375d65>] _raw_spin_lock_irq+0x15/0x30 > > [321182.618449] [<ffffffffa01e2fca>] ? snd_usbmidi_output_drain+0x7a/0x100 [snd_usb_lib] > > [321182.618462] [<ffffffffa01b7699>] ? snd_rawmidi_drain_output+0x119/0x180 [snd_rawmidi] > > I think that bug was introduced by this commit: > http://git.kernel.org/linus/7a17daae8ed71bf3259d905a4fc48a5b424fa935 > which causes the driver to free many internal data structures when > they might still be in use by userspace. > > Please try to revert it. > > I think a proper fix would be to free the URBs/buffers but not the > driver's data structures. > > Takashi, do you remember what the original problem was?
Well, I have only a vague memory -- it's a similar scenario that some app still accessing after disconnection. The URB can't be handled after the disconnection is finished.
I think the patch below might fix in this case. You can try it instead of reverting the commit above.
thanks,
Takashi
--- diff --git a/sound/usb/usbmidi.c b/sound/usb/usbmidi.c index 2c59afd..81c8d85 100644 --- a/sound/usb/usbmidi.c +++ b/sound/usb/usbmidi.c @@ -986,6 +986,8 @@ static void snd_usbmidi_output_drain(struct snd_rawmidi_substream *substream) DEFINE_WAIT(wait); long timeout = msecs_to_jiffies(50); + if (ep->umidi->disconnected) + return; /* * The substream buffer is empty, but some data might still be in the * currently active URBs, so we have to wait for those to complete. @@ -1275,6 +1277,11 @@ void snd_usbmidi_disconnect(struct list_head* p) snd_usbmidi_in_endpoint_delete(ep->in); ep->in = NULL; } + ep->active_urbs = 0; + if (ep->drain_urbs) { + ep->drain_urbs = 0; + wake_up(&ep->drain_wait); + } } del_timer_sync(&umidi->error_timer); }
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