[PATCH v4 2/6] mtd: spi-nor: add Octal DTR support for Macronix flash

[Tudor Ambarus]

Hi, Jaime,

On 08.09.2023 09:43, Jaime Liao wrote:
> From: JaimeLiao <jaimeliao at mxic.com.tw>
> 
> Create Macronix specify method for enable Octal DTR mode and
> set 20 dummy cycles to allow running at the maximum supported
> frequency for Macronix Octal flash.

You didn't answer my question. What happens when you specify 20 dummy
cycles, thus you configure the dummy cycles for the maximum flash speed,
but you program the flash to work on 1 MHz for example. Do you still
have reliable results?
> 
> Use number of dummy cycles which is parse by SFDP then convert
> it to bit pattern and set in CR2 register.

What we should do instead is to determine the flash speed at which the
flash is operated and then to set the correct number of dummy cycles
according to what the flash requires. There should be a table somewhere
in the datasheet that specify a required number of dummy cycles for a
particular frequency, isn't it? Yeah, see "9-3-1. Dummy Cycle and
Frequency Table (MHz)" of the mx66lm1g45g datasheet.

Cheers,
ta