[PATCH] dma: mxs-dma: enable channel in device_issue_pending call

[b32955@freescale.com (Huang Shijie)]

? 2012?04?11? 13:32, Shawn Guo ??:
> Enable channel in device_issue_pending call, so that the order between
> cookie assignment and channel enabling can be ensured naturally.
>
> It fixes the mxs gpmi-nand breakage which is caused by the incorrect
> order of cookie assigning and channel enabling.
>
> Suggested-by: Russell King <rmk+kernel@arm.linux.org.uk>
> Signed-off-by: Shawn Guo <shawn.guo@linaro.org>
> ---
> [resend to cc LAKML, sorry]
>
> Shijie,
>
> I tested the patch with mmc and sound driver.  Can you give it a test
> with gpmi-nand to see if it fixes the problem for you?
>
> Thanks,
> Shawn
>
>  drivers/dma/mxs-dma.c                  |   10 +++-------
>  drivers/mmc/host/mxs-mmc.c             |    3 +++
>  drivers/mtd/nand/gpmi-nand/gpmi-nand.c |    1 +
>  3 files changed, 7 insertions(+), 7 deletions(-)
>
> diff --git a/drivers/dma/mxs-dma.c b/drivers/dma/mxs-dma.c
> index c81ef7e..655d4ce 100644
> --- a/drivers/dma/mxs-dma.c
> +++ b/drivers/dma/mxs-dma.c
> @@ -201,10 +201,6 @@ static struct mxs_dma_chan *to_mxs_dma_chan(struct dma_chan *chan)
>  
>  static dma_cookie_t mxs_dma_tx_submit(struct dma_async_tx_descriptor *tx)
>  {
> -	struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(tx->chan);
> -
> -	mxs_dma_enable_chan(mxs_chan);
> -
>  	return dma_cookie_assign(tx);
>  }
>  
> @@ -558,9 +554,9 @@ static enum dma_status mxs_dma_tx_status(struct dma_chan *chan,
>  
>  static void mxs_dma_issue_pending(struct dma_chan *chan)
>  {
> -	/*
> -	 * Nothing to do. We only have a single descriptor.
> -	 */
> +	struct mxs_dma_chan *mxs_chan = to_mxs_dma_chan(chan);
> +
> +	mxs_dma_enable_chan(mxs_chan);
>  }
>  
>  static int __init mxs_dma_init(struct mxs_dma_engine *mxs_dma)
> diff --git a/drivers/mmc/host/mxs-mmc.c b/drivers/mmc/host/mxs-mmc.c
> index b0f2ef9..e3f5af9 100644
> --- a/drivers/mmc/host/mxs-mmc.c
> +++ b/drivers/mmc/host/mxs-mmc.c
> @@ -363,6 +363,7 @@ static void mxs_mmc_bc(struct mxs_mmc_host *host)
>  		goto out;
>  
>  	dmaengine_submit(desc);
> +	dma_async_issue_pending(host->dmach);
>  	return;
>  
>  out:
> @@ -403,6 +404,7 @@ static void mxs_mmc_ac(struct mxs_mmc_host *host)
>  		goto out;
>  
>  	dmaengine_submit(desc);
> +	dma_async_issue_pending(host->dmach);
>  	return;
>  
>  out:
> @@ -531,6 +533,7 @@ static void mxs_mmc_adtc(struct mxs_mmc_host *host)
>  		goto out;
>  
>  	dmaengine_submit(desc);
> +	dma_async_issue_pending(host->dmach);
>  	return;
>  out:
>  	dev_warn(mmc_dev(host->mmc),
> diff --git a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
> index 75b1dde..9ec51ce 100644
> --- a/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
> +++ b/drivers/mtd/nand/gpmi-nand/gpmi-nand.c
> @@ -266,6 +266,7 @@ int start_dma_without_bch_irq(struct gpmi_nand_data *this,
>  	desc->callback		= dma_irq_callback;
>  	desc->callback_param	= this;
>  	dmaengine_submit(desc);
> +	dma_async_issue_pending(get_dma_chan(this));
>  
>  	/* Wait for the interrupt from the DMA block. */
>  	err = wait_for_completion_timeout(dma_c, msecs_to_jiffies(1000));
Tested-by: Huang Shijie <b32955@freescale.com>