[PATCH 3.2 024/126] ALSA: ali5451: Fix out-of-bound position reporting

Ben Hutchings
2017-02-16T00:35:01Z

From: Takashi Iwai <tiwai@suse.de>

commit db68577966abc1aeae4ec597b3dcfa0d56e92041 upstream.

The pointer callbacks of ali5451 driver may return the value at the
boundary occasionally, and it results in the kernel warning like
snd_ali5451 0000:00:06.0: BUG: , pos = 16384, buffer size = 16384, period size = 1024

It seems that folding the position offset is enough for fixing the
warning and no ill-effect has been seen by that.

Reported-by: Enrico Mioso <mrkiko.rs@gmail.com>
Tested-by: Enrico Mioso <mrkiko.rs@gmail.com>
Signed-off-by: Takashi Iwai <tiwai@suse.de>
Signed-off-by: Ben Hutchings <ben@decadent.org.uk>
---
sound/pci/ali5451/ali5451.c | 2 ++
1 file changed, 2 insertions(+)

--- a/sound/pci/ali5451/ali5451.c
+++ b/sound/pci/ali5451/ali5451.c
@@ -1422,6 +1422,7 @@ snd_ali_playback_pointer(struct snd_pcm_
spin_unlock(&codec->reg_lock);
snd_ali_printk("playback pointer returned cso=%xh.\n", cso);

+ cso %= runtime->buffer_size;
return cso;
}

@@ -1442,6 +1443,7 @@ static snd_pcm_uframes_t snd_ali_pointer
cso = inw(ALI_REG(codec, ALI_CSO_ALPHA_FMS + 2));
spin_unlock(&codec->reg_lock);

+ cso %= runtime->buffer_size;
return cso;
}