Re: [PATCH] mtd: spinand: Enable QE on all dies

[Miquel Raynal]

>> > +	/*
>> > +	 * QE is a per-die setting on some devices. Program each target
>> > +	 * individually when enabling or disabling quad I/O mode.
>> > +	 */
>> > +	for (target = 0; target < nand->memorg.ntargets; target++) {
>> > +		ret = spinand_select_target(spinand, target);
>> > +		if (ret)
>> > +			return ret;
>> > +
>> > +		ret = spinand_upd_cfg(spinand, CFG_QUAD_ENABLE,
>> > +				      enable ? CFG_QUAD_ENABLE : 0);
>> > +		if (ret)
>> > +			return ret;
>> 
>> If there is an issue in the middle of the loop, the chip will become
>> unusable. Perhaps we should reset the dies to the !QE state and return
>> an error to continue in degraded (single) mode if that happens?
>
>
> Single-lane is the most basic op - if the QE set_feature write fails, the link
> is broken and single-lane won't work anyway. And falling back needs the vendor's
> own 1S op stored somewhere, but those variant tables are discarded after probe.
> So it likely requires refactoring struct spinand_device to cache them. Given that,
> maybe just keep the current return-error implementation.

Ack.