Using GPMI-NAND driver on iMX28 using 3.4-rc1?

Shawn Guo shawn.guo at linaro.org
Fri Apr 6 08:49:41 EDT 2012


On Fri, Apr 06, 2012 at 06:34:23PM +0800, Huang Shijie wrote:
...
> It's maybe too late to assign the DMA cookie after
> mxs_dma_enable_chan() in mxs_dma_tx_submit().
> The interrupt may arise before the dma_cookie_assign() finishes.
> 
> Why mmc/audio do not have this bug? their interrupt arise too slow.
> 
> I tested the following code :

Great.  Send a formal patch to Vinod?

Regards,
Shawn

> ==============================================================
> 
> diff --git a/drivers/dma/mxs-dma.c b/drivers/dma/mxs-dma.c
> index 5978113..0f5b09a 100644
> --- a/drivers/dma/mxs-dma.c
> +++ b/drivers/dma/mxs-dma.c
> @@ -202,10 +202,12 @@ static struct mxs_dma_chan
> *to_mxs_dma_chan(struct dma_cha
> 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);
> + dma_cookie_t c;
> 
> + c = dma_cookie_assign(tx);
> mxs_dma_enable_chan(mxs_chan);
> 
> - return dma_cookie_assign(tx);
> + return c;
> }
> 
> static void mxs_dma_tasklet(unsigned long data)
> 



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