Re: [PATCH v2 1/3] mtd: spi-nor: macronix: Drop the redundant flash info fields

From: Pratyush Yadav <pratyush@kernel.org>
To: Cheng Ming Lin <linchengming884@gmail.com>
Cc: Michael Walle <mwalle@kernel.org>,
	 Tudor Ambarus <tudor.ambarus@linaro.org>,
	 Guenter Roeck <linux@roeck-us.net>,
	 Pratyush Yadav <pratyush@kernel.org>,
	 Cheng Ming Lin <chengminglin@mxic.com.tw>,
	miquel.raynal@bootlin.com,  richard@nod.at,  vigneshr@ti.com,
	linux-mtd@lists.infradead.org,  linux-kernel@vger.kernel.org,
	alvinzhou@mxic.com.tw,  leoyu@mxic.com.tw,
	 Maarten Zanders <maarten@zanders.be>
Subject: Re: [PATCH v2 1/3] mtd: spi-nor: macronix: Drop the redundant flash info fields
Date: Tue, 30 Sep 2025 14:19:29 +0200	[thread overview]
Message-ID: <mafs01pnoceum.fsf@kernel.org> (raw)
In-Reply-To: <CAAyq3SYyqi-oR8T039Zd0uaF6UieX3SdF9UF2kxOG6+yJqAEUg@mail.gmail.com> (Cheng Ming Lin's message of "Tue, 30 Sep 2025 15:36:40 +0800")

On Tue, Sep 30 2025, Cheng Ming Lin wrote:

> Hi Michael,
>
> Michael Walle <mwalle@kernel.org> 於 2025年9月24日 週三 下午8:11寫道：
>>
>> > The root cause of this problem lies in the failure of parsing the SFDP
>> > data for the flash, rather than an issue with the patch itself. I believe
>> > we should not revert this patch.
>>
>> I disagree. There are Macronix flashes with that ID which doesn't
>> have SFDP.  And this patch is dropping support for them. See also
>> [1]. Now I'm not sure it is worth reverting this commit. Nobody,
>> except Guenter complained, but only *so far* (and that patch is in
>> since 6.16). Any opinions?

When I read this I was just hoping no one complains and we end up just
dropping support for these flashes that no one seems to use...

>
> I agree with reverting this patch. When I initially verified it, the
> devices I had on hand all supported SFDP, so I did not catch this issue.
> After checking again, I confirm that some older flashes without SFDP are
> indeed affected.

Do you know if these flashes are used in any devices that are actively
used and maintained? If so, we should revert. If it is likely they
aren't actively used, then maybe we just keep things as they are?
Dunno...

>
> Would it make sense to only change the `.name` field to use a comment,
> while keeping the rest as is? That way we can still support flashes that
> may not provide SFDP.

Sure, that would be a good improvement over a plain revert. Maybe as a
follow up patch to the revert?

-- 
Regards,
Pratyush Yadav

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