Re: Ooops when working with USB MIDI (2.6.33.1)

Takashi Iwai
2010-04-09T07:29:38Z

At Fri, 9 Apr 2010 07:51:35 +0100,
Tvrtko Ursulin wrote:
>
> On Thursday 08 Apr 2010 13:22:36 Takashi Iwai wrote:
> > > 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);
> > }
>
> For the second hunk, do you think ep->out->... and so on? That would be more
> in-line with code present in 2.6.33.

Ah, crap. Sorry, that's just messing up.
The revised (compiled but untested) patch is below.

thanks,

Takashi

---
diff --git a/sound/usb/usbmidi.c b/sound/usb/usbmidi.c
index 2c59afd..9e28b20 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.
@@ -1123,14 +1125,21 @@ static int snd_usbmidi_in_endpoint_create(struct snd_usb_midi* umidi,
* 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);
}

@@ -1262,15 +1271,18 @@ void snd_usbmidi_disconnect(struct list_head* p)
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;