1 files changed, 16 insertions, 1 deletions

diff --git a/sound/soc/fsl/mpc5200_psc_ac97.c b/sound/soc/fsl/mpc5200_psc_ac97.c
index 794a247b3eb..7eb549985d4 100644
--- a/sound/soc/fsl/mpc5200_psc_ac97.c
+++ b/sound/soc/fsl/mpc5200_psc_ac97.c
@@ -34,13 +34,20 @@ static unsigned short psc_ac97_read(struct snd_ac97 *ac97, unsigned short reg)
 	int status;
 	unsigned int val;
 
+	mutex_lock(&psc_dma->mutex);
+
 	/* Wait for command send status zero = ready */
 	status = spin_event_timeout(!(in_be16(&psc_dma->psc_regs->sr_csr.status) &
 				MPC52xx_PSC_SR_CMDSEND), 100, 0);
 	if (status == 0) {
 		pr_err("timeout on ac97 bus (rdy)\n");
+		mutex_unlock(&psc_dma->mutex);
 		return -ENODEV;
 	}
+
+	/* Force clear the data valid bit */
+	in_be32(&psc_dma->psc_regs->ac97_data);
+
 	/* Send the read */
 	out_be32(&psc_dma->psc_regs->ac97_cmd, (1<<31) | ((reg & 0x7f) << 24));
 
@@ -50,16 +57,19 @@ static unsigned short psc_ac97_read(struct snd_ac97 *ac97, unsigned short reg)
 	if (status == 0) {
 		pr_err("timeout on ac97 read (val) %x\n",
 				in_be16(&psc_dma->psc_regs->sr_csr.status));
+		mutex_unlock(&psc_dma->mutex);
 		return -ENODEV;
 	}
 	/* Get the data */
 	val = in_be32(&psc_dma->psc_regs->ac97_data);
 	if (((val >> 24) & 0x7f) != reg) {
 		pr_err("reg echo error on ac97 read\n");
+		mutex_unlock(&psc_dma->mutex);
 		return -ENODEV;
 	}
 	val = (val >> 8) & 0xffff;
 
+	mutex_unlock(&psc_dma->mutex);
 	return (unsigned short) val;
 }
 
@@ -68,16 +78,21 @@ static void psc_ac97_write(struct snd_ac97 *ac97,
 {
 	int status;
 
+	mutex_lock(&psc_dma->mutex);
+
 	/* Wait for command status zero = ready */
 	status = spin_event_timeout(!(in_be16(&psc_dma->psc_regs->sr_csr.status) &
 				MPC52xx_PSC_SR_CMDSEND), 100, 0);
 	if (status == 0) {
 		pr_err("timeout on ac97 bus (write)\n");
-		return;
+		goto out;
 	}
 	/* Write data */
 	out_be32(&psc_dma->psc_regs->ac97_cmd,
 			((reg & 0x7f) << 24) | (val << 8));
+
+ out:
+	mutex_unlock(&psc_dma->mutex);
 }
 
 static void psc_ac97_warm_reset(struct snd_ac97 *ac97)