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

From: Miquel Raynal <miquel.raynal@bootlin.com>
To: "han.xu" <han.xu@oss.nxp.com>
Cc: Richard Weinberger <richard@nod.at>,
	 Vignesh Raghavendra <vigneshr@ti.com>,
	 Peter Pan <peterpandong@micron.com>,
	 Boris Brezillon <bbrezillon@kernel.org>,
	 linux-mtd@lists.infradead.org, linux-kernel@vger.kernel.org,
	 Han Xu <han.xu@nxp.com>
Subject: Re: [PATCH] mtd: spinand: Enable QE on all dies
Date: Thu, 13 Aug 2026 08:48:47 +0200	[thread overview]
Message-ID: <87v79eldm8.fsf@bootlin.com> (raw)
In-Reply-To: <anowMUOYurNYphfU@cozumel> (han xu's message of "Wed, 12 Aug 2026 11:34:26 -0500")

>> > +	/*
>> > +	 * 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.

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