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>

diff --git a/sound/soc/fsl/mpc5200_dma.c b/sound/soc/fsl/mpc5200_dma.c
index efec33a..f0a2d40 100644 (file)
--- 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;

diff --git a/sound/soc/fsl/mpc5200_dma.h b/sound/soc/fsl/mpc5200_dma.h
index 2000803..8d396bb 100644 (file)
--- a/sound/soc/fsl/mpc5200_dma.h
+++ b/sound/soc/fsl/mpc5200_dma.h
@@ -55,6 +55,7 @@ struct psc_dma {
        unsigned int irq;
        struct device *dev;
        spinlock_t lock;
+       struct mutex mutex;
        u32 sicr;
        uint sysclk;
        int imr;

diff --git a/sound/soc/fsl/mpc5200_psc_ac97.c b/sound/soc/fsl/mpc5200_psc_ac97.c
index 9b8503f..7eb5499 100644 (file)
--- a/sound/soc/fsl/mpc5200_psc_ac97.c
+++ b/sound/soc/fsl/mpc5200_psc_ac97.c
@@ -34,11 +34,14 @@ 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;
        }
 
@@ -54,16 +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;
 }
 
@@ -72,16 +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)