[PATCH] mtd: spi-nor: core: Introduce spi_nor_abort_octal_dtr()

[liao jaime]

Hi Michael

>
> > Some flashes contains 8D_8D_8D information in SFDP but did not enter
> > octal DTR mode if conditions are not satisfied.
>
> What exactly are these conditions? Rather than "abort" the octal mode,
> the flash shouldn't have that capability in the first place.
"Abort" is not a good word.
Is it better for using "discard"?
3 conditions should be satisfied before enable octal dtr mode.
1. function hook in nor->params->set_octal_dtr
2. nor->read_proto and nor->write_proto are SNOR_PROTO_8_8_8_DTR
3. nor->flags & SNOR_F_IO_MODE_EN_VOLATILE
Flash driver still bring 8D_8D_8D protocol instructions in 1s-1s-1s mode if
conditions are not satisfied.
In a case, flash ID didn't include in vendor's ID table.
It will be "spi-nor-generic".
8D-8D-8D information could be parsed in SFDP but nor->params->set_octal_dtr
didn't hook vendor specific function for enabling octal dtr mode.
So that it still bring 8D protocol in 1s-1s-1s mode and have no chance
to select 1-1-8 protocol.
I think it may better to re-select a suitable protocol for this case.

>
> -michael
Thanks
Jaime