Re: [PATCH] mtd: onenand: omap2: Pass correct flags for prep_dma_memcpy

From: H. Nikolaus Schaller
Date: Sat Jan 04 2020 - 03:47:32 EST



> Am 04.01.2020 um 08:34 schrieb Peter Ujfalusi <peter.ujfalusi@xxxxxx>:
>
> The commit converting the driver to DMAengine was missing the flags for
> the memcpy prepare call.
> It went unnoticed since the omap-dma drive was ignoring them.

s/drive/driver/

>
> Fixes: 3ed6a4d1de2c5 (" mtd: onenand: omap2: Convert to use dmaengine for memcp")
> Reported-by: Aaro Koskinen <aaro.koskinen@xxxxxx>
> Signed-off-by: Peter Ujfalusi <peter.ujfalusi@xxxxxx>
> ---
> Hi,
>
> Aaro reported [1] a failure on omap2-onenand pointing to
> 4689d35c765c696bdf0535486a990038b242a26b. It looks like the root cause is the
> conversion of omap2-onenand to DMAengine which missed the flags.
>
> Basically the client is waiting for a callback without asking for it. This
> certainly causes timeout.
>
> I have not tested the patch, but it should fix the issue.

makes the gta04a5one.dts work again.

Tested-by: H. Nikolaus Schaller <hns@xxxxxxxxxxxxx>

BR and thanks!
Nikolaus

>
> [1] https://lore.kernel.org/lkml/20200103081726.GD15023@xxxxxxxxxxxxxxxxxxxxxxxxx/
>
> drivers/mtd/nand/onenand/omap2.c | 3 ++-
> 1 file changed, 2 insertions(+), 1 deletion(-)
>
> diff --git a/drivers/mtd/nand/onenand/omap2.c b/drivers/mtd/nand/onenand/omap2.c
> index edf94ee54ec7..71a632b815aa 100644
> --- a/drivers/mtd/nand/onenand/omap2.c
> +++ b/drivers/mtd/nand/onenand/omap2.c
> @@ -328,7 +328,8 @@ static inline int omap2_onenand_dma_transfer(struct omap2_onenand *c,
> struct dma_async_tx_descriptor *tx;
> dma_cookie_t cookie;
>
> - tx = dmaengine_prep_dma_memcpy(c->dma_chan, dst, src, count, 0);
> + tx = dmaengine_prep_dma_memcpy(c->dma_chan, dst, src, count,
> + DMA_CTRL_ACK | DMA_PREP_INTERRUPT);
> if (!tx) {
> dev_err(&c->pdev->dev, "Failed to prepare DMA memcpy\n");
> return -EIO;
> --
> Peter
>
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