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

[Marek Vasut <marek.vasut@gmail.com>]

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@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.

> The working board has
> 
> => fli
> 
> Bank # 1: CFI conformant flash (16 x 16)  Size: 128 MB in 1024 Sectors
>   AMD Standard command set, Manufacturer ID: 0x01, Device ID: 0x227E2801
>   Erase timeout: 2048 ms, write timeout: 1 ms
>   Buffer write timeout: 3 ms, buffer size: 512 bytes
> 
> The failing board has
> 
> => fli
> 
> Bank # 1: CFI conformant flash (16 x 16)  Size: 128 MB in 1024 Sectors
>   AMD Standard command set, Manufacturer ID: 0x01, Device ID: 0x227E2801
>   Erase timeout: 4096 ms, write timeout: 1 ms
>   Buffer write timeout: 3 ms, buffer size: 64 bytes
> 
> Can you investigate?
> 
> York
> 


-- 
Best regards,
Marek Vasut