Received-SPF: pass (google.com: domain of linux-kernel+bounces-63431-linux.lists.archive=gmail.com@vger.kernel.org designates 2604:1380:40f1:3f00::1 as permitted sender) client-ip=2604:1380:40f1:3f00::1;
Date: Tue, 13 Feb 2024 12:21:46 +0100
From: Francesco Dolcini <francesco@dolcini.it>
To: Sasha Levin <sashal@kernel.org>, stable@vger.kernel.org,
	Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc: Alexander Stein <alexander.stein@ew.tq-group.com>,
	Shawn Guo <shawnguo@kernel.org>, linux-kernel@vger.kernel.org,
	linux-arm-kernel@lists.infradead.org, regressions@lists.linux.dev,
	Max Krummenacher <max.krummenacher@toradex.com>,
	Miquel Raynal <miquel.raynal@bootlin.com>
Subject: Regression, i.MX7 boot failure, Linux v6.1.77
Message-ID: <20240213112146.GA5874@francesco-nb>
Precedence: bulk
MIME-Version: 1.0
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline

Hello Sasha,
kernel v6.1.77 introduces a regression, with a boot failure, on i.MX7,
with commit db30f469ae8b ("ARM: dts: imx7s: Fix nand-controller #size-cells").

The issue is known [1][2], changing `#size-cells = <0>` is formally
correct, but do not play well with the firmware that are deployed on
those embedded devices, leading to a boot failure.

A mitigation was implemented in the Linux kernel,
commit 84549c816dc3 ("mtd: parsers: ofpart: add workaround for #size-cells 0")
that was merged into v6.3, the firmware was also fixed, however existing
device using old firmware will not boot anymore if updating to a newer
kernel.

I would ask you to drop such a patch from any stable patches queue and
not backport it to any older kernel.

To fix v6.1.y I see two options:
 - backport 84549c816dc3
 - revert db30f469ae8b

What do you prefer? Should I send myself a patch?

[1] https://lore.kernel.org/all/Y4dgBTGNWpM6SQXI@francesco-nb.int.toradex.com/
[2] https://lore.kernel.org/all/20221202071900.1143950-1-francesco@dolcini.it/

Francesco