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

[Luca Ellero]

Hi Stefan,

On 12/12/2014 09:43, Stefan Roese wrote:
> Hi Luca,
>
> 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 at 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.


-- 
Luca Ellero

E-mail: luca.ellero at brickedbrain.com
Internet: www.brickedbrain.com