[U-Boot] mtd: cfi: Add support for status register polling

[York Sun]

On 11/17/2017 11:04 AM, Marek Vasut wrote:
> On 11/17/2017 08:02 PM, Marek Vasut wrote:
>> On 11/17/2017 05:43 PM, York Sun wrote:
>>> On 09/12/2017 10:09 AM, Marek Vasut wrote:
>>>> The status register is optional in the AMD command sets, but it's
>>>> presence can be checked by reading out CFI table entry 0xc bit 0.
>>>> If the register is present, prefer using it's bit 7 to determine
>>>> if the flash is busy over reading the flash ; this is needed ie.
>>>> on Hyperflash memories.
>>>>
>>>> Signed-off-by: Marek Vasut <marek.vasut+renesas at gmail.com>
>>>> ---
>>>
>>> Marek,
>>>
>>> Some of our boards failed. I traced to this commit. Reverting this
>>> commit fixes the issue. I happen to have two boards with slightly
>>> different flash chip. One works and the other doesn't.
>>
>> I can't since I don't have the board with such a chip ...
>> Which chip is that ? Mine is Spansion S25KL256 hyperflash.
> 
> S26KL256S (26 instead of 25), sorry.
> 

My local board has chip S29GL01GS11TFIV1. The remote board has identical
manufacture ID and device ID. I guess they are the same part (maybe
different speed grade though). I haven't heard from the team who can
visually check the part number for me.

York