[U-Boot] [PATCH] mtd: nand: mxs: fix PIO_WORD number

Stefan Roese
2014-12-12T12:43:22Z

Hi Luca,

On 12.12.2014 13:40, Luca Ellero wrote:
>> On 10.12.2014 09:24, Luca Ellero wrote:
>>> There is only one pio_word in this DMA transaction so data field must
>>> be 1.
>>>
>>> Signed-off-by: Luca Ellero <luca.ellero@brickedbrain.com>
>>> ---
>>> drivers/mtd/nand/mxs_nand.c | 2 +-
>>> 1 file changed, 1 insertion(+), 1 deletion(-)
>>>
>>> diff --git a/drivers/mtd/nand/mxs_nand.c b/drivers/mtd/nand/mxs_nand.c
>>> index 7a064ab..616c9ca 100644
>>> --- a/drivers/mtd/nand/mxs_nand.c
>>> +++ b/drivers/mtd/nand/mxs_nand.c
>>> @@ -305,7 +305,7 @@ static void mxs_nand_cmd_ctrl(struct mtd_info
>>> *mtd, int data, unsigned int ctrl)
>>> d->cmd.data =
>>> MXS_DMA_DESC_COMMAND_DMA_READ | MXS_DMA_DESC_IRQ |
>>> MXS_DMA_DESC_CHAIN | MXS_DMA_DESC_DEC_SEM |
>>> - MXS_DMA_DESC_WAIT4END | (3 << MXS_DMA_DESC_PIO_WORDS_OFFSET) |
>>> + MXS_DMA_DESC_WAIT4END | (1 << MXS_DMA_DESC_PIO_WORDS_OFFSET) |
>>> (nand_info->cmd_queue_len << MXS_DMA_DESC_BYTES_OFFSET);
>>
>> What error or problem does this incorrect setup cause in your case? I'm
>> asking since I'm also using this driver in some mx6 system and have not
>> seen any issues.
>
> As far as I can see, it doesn't seem to cause any issue. But, if you
> read the iMX6 Reference Manual (chapter 14.2) this field should reflect
> the number of PIO_WORDS appended to the DMA command, in this case 1.

Okay. I just wanted to check if this patch fixes a real problem that you
have experienced. Thanks for the explanation.

Reviewed-by: Stefan Roese <sr@denx.de>

Thanks,
Stefan