ASoC: au1x: psc-ac97: verify correct codec register was read

Verify that the correct register has been received from the codec.

Signed-off-by: Manuel Lauss <manuel.lauss@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

1 files changed, 8 insertions, 3 deletions

diff --git a/sound/soc/au1x/psc-ac97.c b/sound/soc/au1x/psc-ac97.c
index a521aa90ddee..efe2afd4fe24 100644
--- a/sound/soc/au1x/psc-ac97.c
+++ b/sound/soc/au1x/psc-ac97.c
@@ -61,7 +61,8 @@ static unsigned short au1xpsc_ac97_read(struct snd_ac97 *ac97,
 {
         /* FIXME */
         struct au1xpsc_audio_data *pscdata = au1xpsc_ac97_workdata;
-        unsigned short data, retry, tmo;
+        unsigned short retry, tmo;
+        unsigned long data;
 
         au_writel(PSC_AC97EVNT_CD, AC97_EVNT(pscdata));
         au_sync();
@@ -79,15 +80,19 @@ static unsigned short au1xpsc_ac97_read(struct snd_ac97 *ac97,
                         && --tmo)
                         udelay(2);
 
-                data = au_readl(AC97_CDC(pscdata)) & 0xffff;
+                data = au_readl(AC97_CDC(pscdata));
 
                 au_writel(PSC_AC97EVNT_CD, AC97_EVNT(pscdata));
                 au_sync();
 
                 mutex_unlock(&pscdata->lock);
+
+                if (reg != ((data >> 16) & 0x7f))
+                        tmo = 1;        /* wrong register, try again */
+
         } while (--retry && !tmo);
 
-        return retry ? data : 0xffff;
+        return retry ? data & 0xffff : 0xffff;
 }
 
 /* AC97 controller writes to codec register */