ALSA: hda - Don't assume non-NULL PCM ops
The PCM ops might be set NULL, or cleared to NULL when the driver is
unbound. Give a proper NULL check at each place to be more robust.
Signed-off-by: Takashi Iwai <tiwai@suse.de>
diff --git a/sound/pci/hda/hda_codec.c b/sound/pci/hda/hda_codec.c
index 20283be..3bd9158 100644
--- a/sound/pci/hda/hda_codec.c
+++ b/sound/pci/hda/hda_codec.c
@@ -4525,7 +4525,11 @@
{
int ret;
mutex_lock(&codec->bus->prepare_mutex);
- ret = hinfo->ops.prepare(hinfo, codec, stream, format, substream);
+ if (hinfo->ops.prepare)
+ ret = hinfo->ops.prepare(hinfo, codec, stream, format,
+ substream);
+ else
+ ret = -ENODEV;
if (ret >= 0)
purify_inactive_streams(codec);
mutex_unlock(&codec->bus->prepare_mutex);
@@ -4546,7 +4550,8 @@
struct snd_pcm_substream *substream)
{
mutex_lock(&codec->bus->prepare_mutex);
- hinfo->ops.cleanup(hinfo, codec, substream);
+ if (hinfo->ops.cleanup)
+ hinfo->ops.cleanup(hinfo, codec, substream);
mutex_unlock(&codec->bus->prepare_mutex);
}
EXPORT_SYMBOL_GPL(snd_hda_codec_cleanup);