ALSA: usb-audio: Fix substream assignments

In 3.5 kernel, the endpoint is assigned dynamically for the
substreams, but the PCM assignment still checks the presence of the
endpoint pointer.  This ended up in duplicated PCM substream creations
at probing time, resulting in kernel warnings like:

WARNING: at fs/proc/generic.c:586 proc_register+0x169/0x1a6()
Pid: 1152, comm: modprobe Not tainted 3.5.0-rc1-00110-g71fae7e #2
Call Trace:
 [<ffffffff8102a400>] warn_slowpath_common+0x83/0x9c
 [<ffffffff8102a4bc>] warn_slowpath_fmt+0x46/0x48
 [<ffffffff813829ad>] ? add_preempt_count+0x39/0x3b
 [<ffffffff811292f0>] proc_register+0x169/0x1a6
 [<ffffffff8112962e>] create_proc_entry+0x74/0x8c
 [<ffffffffa018eb63>] snd_info_register+0x3e/0xc3 [snd]
 [<ffffffffa01fde2e>] snd_pcm_new_stream+0xb1/0x404 [snd_pcm]
 [<ffffffffa024861f>] snd_usb_add_audio_stream+0xd2/0x230 [snd_usb_audio]
 [<ffffffffa0241d33>] ? snd_usb_parse_audio_format+0x252/0x34f [snd_usb_audio]
 [<ffffffff810d6b17>] ? kmem_cache_alloc_trace+0xab/0xbb
 [<ffffffffa0248c29>] snd_usb_parse_audio_interface+0x4ac/0x567 [snd_usb_audio]
 [<ffffffffa023f0ff>] snd_usb_create_stream+0xe9/0x125 [snd_usb_audio]
 [<ffffffffa023f9b1>] usb_audio_probe+0x62a/0x72c [snd_usb_audio]
 .....

This patch fixes the regression by checking the fixed endpoint number
for each substream instead of the endpoint pointer.

Reported-and-tested-by: Jamie Heilman <jamie@audible.transient.net>
Signed-off-by: Takashi Iwai <tiwai@suse.de>

diff --git a/sound/usb/card.h b/sound/usb/card.h
index 0d37238b84572fed54cef1c89ee23e1d44d8ae00..2b9fffff23b62a5449d39f2a4b03cbaadb1529a6 100644 (file)
--- a/sound/usb/card.h
+++ b/sound/usb/card.h
@@ -119,6 +119,7 @@ struct snd_usb_substream {
        unsigned long unlink_mask;      /* bitmask of unlinked urbs */
 
        /* data and sync endpoints for this stream */
+       unsigned int ep_num;            /* the endpoint number */
        struct snd_usb_endpoint *data_endpoint;
        struct snd_usb_endpoint *sync_endpoint;
        unsigned long flags;

diff --git a/sound/usb/stream.c b/sound/usb/stream.c
index 6b7d7a2b7baa3a83c68e35917d95515a3caa482a..083ed81160e58b094ee8f4fca637371aa5b5fff4 100644 (file)
--- a/sound/usb/stream.c
+++ b/sound/usb/stream.c
@@ -97,6 +97,7 @@ static void snd_usb_init_substream(struct snd_usb_stream *as,
        subs->formats |= fp->formats;
        subs->num_formats++;
        subs->fmt_type = fp->fmt_type;
+       subs->ep_num = fp->endpoint;
 }
 
 /*
@@ -119,9 +120,7 @@ int snd_usb_add_audio_stream(struct snd_usb_audio *chip,
                if (as->fmt_type != fp->fmt_type)
                        continue;
                subs = &as->substream[stream];
-               if (!subs->data_endpoint)
-                       continue;
-               if (subs->data_endpoint->ep_num == fp->endpoint) {
+               if (subs->ep_num == fp->endpoint) {
                        list_add_tail(&fp->list, &subs->fmt_list);
                        subs->num_formats++;
                        subs->formats |= fp->formats;
@@ -134,7 +133,7 @@ int snd_usb_add_audio_stream(struct snd_usb_audio *chip,
                if (as->fmt_type != fp->fmt_type)
                        continue;
                subs = &as->substream[stream];
-               if (subs->data_endpoint)
+               if (subs->ep_num)
                        continue;
                err = snd_pcm_new_stream(as->pcm, stream, 1);
                if (err < 0)