Re: [PATCH] mtd: spi-nor: enable 4B opcodes for n25q256a

From: Marek Vasut
Date: Fri May 03 2019 - 07:28:11 EST


On 5/3/19 12:37 PM, Simon Goldschmidt wrote:
> On Fri, May 3, 2019 at 12:00 PM Marek Vasut <marek.vasut@xxxxxxxxx> wrote:
>>
>> On 5/3/19 10:53 AM, Simon Goldschmidt wrote:
>>> Tested on socfpga cyclone5 where this is required to ensure that the
>>> boot rom can access this flash after warm reboot.
>>
>> Are you sure _all_ variants of the N25Q256 support 4NB opcodes ?
>> I think there were some which didn't, but I might be wrong.
>
> Oh, damn, you're right. The documentation [1] statest that 4-byte erase and
> program opcodes are only supported for part numbers N25Q256A83ESF40x,
> N25Q256A83E1240x and N25QA83ESFA0F.

;-)

> Any idea of how I can still enable 4-byte opcodes for my chip?
Maybe SFDP tables contains some information whether the chip supports
the 4B opcodes ?

--
Best regards,
Marek Vasut