On Thu, Jul 2, 2009 at 1:57 PM, Grant Likely<grant.likely@xxxxxxxxxxxx> wrote:
> From: Grant Likely <grant.likely@xxxxxxxxxxxx>
>
> 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@xxxxxxxxxxxx>
Acked-by: Jon Smirl <jonsmirl@xxxxxxxxx>
> ---
>
> sound/soc/fsl/mpc5200_dma.c | 1 +
> sound/soc/fsl/mpc5200_dma.h | 1 +
> sound/soc/fsl/mpc5200_psc_ac97.c | 13 ++++++++++++-
> 3 files changed, 14 insertions(+), 1 deletions(-)
>
>
> diff --git a/sound/soc/fsl/mpc5200_dma.c b/sound/soc/fsl/mpc5200_dma.c
> index efec33a..f0a2d40 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;
> diff --git a/sound/soc/fsl/mpc5200_dma.h b/sound/soc/fsl/mpc5200_dma.h
> index 2000803..8d396bb 100644
> --- 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
> --- 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)
>
>
--
Jon Smirl
jonsmirl@xxxxxxxxx
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