| Date | Thu, 22 Apr 2010 12:09:09 -0700 | From | Greg KH <> | Subject | [098/197] ALSA: usb - Fix Oops after usb-midi disconnection |
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2.6.32-stable review patch. If anyone has any objections, please let us know.
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From: Takashi Iwai <tiwai@suse.de>
commit 29aac005ff4dc8a5f50b80f4e5c4f59b21c0fb50 upstream.
usb-midi causes sometimes Oops at snd_usbmidi_output_drain() after disconnection. This is due to the access to the endpoints which have been already released at disconnection while the files are still alive.
This patch fixes the problem by checking disconnection state at snd_usbmidi_output_drain() and by releasing urbs but keeping the endpoint instances until really all freed.
Tested-by: Tvrtko Ursulin <tvrtko@ursulin.net> Signed-off-by: Takashi Iwai <tiwai@suse.de> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
--- sound/usb/usbmidi.c | 24 ++++++++++++++++++------ 1 file changed, 18 insertions(+), 6 deletions(-)
--- a/sound/usb/usbmidi.c +++ b/sound/usb/usbmidi.c @@ -931,6 +931,8 @@ static void snd_usbmidi_output_drain(str 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. @@ -1075,14 +1077,21 @@ static unsigned int snd_usbmidi_count_bi * Frees an output endpoint. * May be called when ep hasn't been initialized completely. */ -static void snd_usbmidi_out_endpoint_delete(struct snd_usb_midi_out_endpoint* ep) +static void snd_usbmidi_out_endpoint_clear(struct snd_usb_midi_out_endpoint *ep) { unsigned int i; for (i = 0; i < OUTPUT_URBS; ++i) - if (ep->urbs[i].urb) + if (ep->urbs[i].urb) { free_urb_and_buffer(ep->umidi, ep->urbs[i].urb, ep->max_transfer); + ep->urbs[i].urb = NULL; + } +} + +static void snd_usbmidi_out_endpoint_delete(struct snd_usb_midi_out_endpoint *ep) +{ + snd_usbmidi_out_endpoint_clear(ep); kfree(ep); } @@ -1201,15 +1210,18 @@ void snd_usbmidi_disconnect(struct list_ usb_kill_urb(ep->out->urbs[j].urb); if (umidi->usb_protocol_ops->finish_out_endpoint) umidi->usb_protocol_ops->finish_out_endpoint(ep->out); + ep->out->active_urbs = 0; + if (ep->out->drain_urbs) { + ep->out->drain_urbs = 0; + wake_up(&ep->out->drain_wait); + } } if (ep->in) for (j = 0; j < INPUT_URBS; ++j) usb_kill_urb(ep->in->urbs[j]); /* free endpoints here; later call can result in Oops */ - if (ep->out) { - snd_usbmidi_out_endpoint_delete(ep->out); - ep->out = NULL; - } + if (ep->out) + snd_usbmidi_out_endpoint_clear(ep->out); if (ep->in) { snd_usbmidi_in_endpoint_delete(ep->in); ep->in = NULL;
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