[ALSA] check for linked substreams of different cards

It is possible to have linked substreams that belong to different cards
and/or different drivers.  This patch changes some drivers to make sure
that they do not incorrectly try to handle substreams of a different
card.

Signed-off-by: Clemens Ladisch <clemens@ladisch.de>
Signed-off-by: Jaroslav Kysela <perex@suse.cz>

1 files changed, 3 insertions, 0 deletions

diff --git a/sound/pci/emu10k1/p16v.c b/sound/pci/emu10k1/p16v.c
index 7ee19c63c2c8..6ace1076c19b 100644
--- a/sound/pci/emu10k1/p16v.c
+++ b/sound/pci/emu10k1/p16v.c
@@ -448,6 +448,9 @@ static int snd_p16v_pcm_trigger_playback(struct snd_pcm_substream *substream,
                 break;
         }
         snd_pcm_group_for_each_entry(s, substream) {
+                if (snd_pcm_substream_chip(s) != emu ||
+                    s->stream != SNDRV_PCM_STREAM_PLAYBACK)
+                        continue;
                 runtime = s->runtime;
                 epcm = runtime->private_data;
                 channel = substream->pcm->device-emu->p16v_device_offset;