ASoC: add locking to mpc5200-psc-ac97 driver

AC97 bus register read/write hooks need to provide locking, but the
mpc5200-psc-ac97 driver does not.  This patch adds a mutex around
the register access routines.

Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Acked-by: Jon Smirl <jonsmirl@gmail.com>
Signed-off-by: Mark Brown <broonie@opensource.wolfsonmicro.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/sound/soc/fsl/mpc5200_dma.c b/sound/soc/fsl/mpc5200_dma.c
index efec33a1c5bd..f0a2d4071998 100644
--- a/sound/soc/fsl/mpc5200_dma.c
+++ b/sound/soc/fsl/mpc5200_dma.c
@@ -456,6 +456,7 @@ int mpc5200_audio_dma_create(struct of_device *op)
                 return -ENODEV;
 
         spin_lock_init(&psc_dma->lock);
+        mutex_init(&psc_dma->mutex);
         psc_dma->id = be32_to_cpu(*prop);
         psc_dma->irq = irq;
         psc_dma->psc_regs = regs;