Re: [PATCH v4 16/27] mtd: spi-nor: Create a local SR cache

[Miquel Raynal <miquel.raynal@bootlin.com>]

>>> In order to be able to generate debugfs output without having to
>>> actually reach the flash, create a SPI NOR local cache of the status
>>> registers. What matters in our case are all the bits related to sector
>>> locking. As such, in order to make it clear that this cache is not
>>> intended to be used anywhere else, we zero the irrelevant bits.
>>>
>>> The cache is initialized once during the early init, and then maintained
>>> every time the write protection scheme is updated.
>>
>> What is the reason for doing so? Do the reads have side effects?
>
> I don't like that a debugfs read will issue a SPI transaction, at
> least not these informational files.
>
> If we ever want to access the registers in the flash, we should have
> a separate debugfs file/interface.

Indeed, the intent was to be able to generate complete debugfs output
without any physical access.

Thanks,
Miquèl