[U-Boot] [UBOOT][PATCH 5/5] am43xx: add delay before xfer

[Jagan Teki]

On Thu, Dec 19, 2013 at 11:24 AM, Sourav Poddar <sourav.poddar at ti.com> wrote:
> On Thursday 19 December 2013 11:24 AM, Jagan Teki wrote:
>>
>> On Thu, Dec 19, 2013 at 10:35 AM, Sourav Poddar<sourav.poddar at ti.com>
>> wrote:
>>>
>>> On Thursday 19 December 2013 12:17 AM, Jagan Teki wrote:
>>>>
>>>> On Thu, Nov 14, 2013 at 9:09 PM, Sourav Poddar<sourav.poddar at ti.com>
>>>> wrote:
>>>>>
>>>>> Without this delay, write/read is failing.
>>>>> Looks like, the WIP always remain set and hence a timeout
>>>>> occurs leading to the error.
>>>>>
>>>>> Signed-off-by: Sourav Poddar<sourav.poddar at ti.com>
>>>>> ---
>>>>> Hi Jagan,
>>>>> This patch seems to be necessary for read/write.
>>>>> I tested by changing few timing variables, but it did not help.
>>>>> The same driver works on J6 with a differnet flash(S25FL256S).
>>>>> Is any one tested macronix flash at uboot?
>>>>
>>>> Delay must be for macronix?
>>>> or common for all flashes.
>>>>
>>> For macronix.
>>
>> All kind of micron parts or any specific..
>> bcz this delay seems to be not- a reasonable.
>>
> that I am not sure as I have only one macronix
> flash to test with

Honestly, I don't recommend to use standalone delay with works for
specific to flash part.
That even harm your driver as well...
Please try to identify the fix - can you send the data-sheet link you
referred to this part...

Also please try to post the bug log w/o delay..if possible.

>
>>>> I haven't tested macronix
>>>>
>>>>>    drivers/spi/ti_qspi.c |    3 +++
>>>>>    1 files changed, 3 insertions(+), 0 deletions(-)
>>>>>
>>>>> diff --git a/drivers/spi/ti_qspi.c b/drivers/spi/ti_qspi.c
>>>>> index 5666250..aa7b6ae 100644
>>>>> --- a/drivers/spi/ti_qspi.c
>>>>> +++ b/drivers/spi/ti_qspi.c
>>>>> @@ -285,6 +285,9 @@ int spi_xfer(struct spi_slave *slave, unsigned int
>>>>> bitlen, const void *dout,
>>>>>                   qslave->cmd |= QSPI_3_PIN;
>>>>>           qslave->cmd |= 0xfff;
>>>>>
>>>>> +#ifdef CONFIG_AM43XX
>>>>> +       udelay(100);
>>>>> +#endif
>
>



-- 
Thanks,
Jagan.
--------
Jagannadha Sutradharudu Teki,
E: jagannadh.teki at gmail.com, P: +91-9676773388
Engineer - System Software Hacker
U-boot - SPI Custodian and Zynq APSOC
Ln: http://www.linkedin.com/in/jaganteki