linux-kernel - Re: [BUG] 6.16-rc7: lockdep failure with max77620-gpio/max77686-rtc

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Message-ID: <68c210a2-49b2-4fd2-97ad-27af85369d9f@sirena.org.uk>
Date: Thu, 31 Jul 2025 13:31:32 +0100
From: Mark Brown <broonie@...nel.org>
To: "Russell King (Oracle)" <linux@...linux.org.uk>
Cc: Krzysztof Kozlowski <krzk@...nel.org>,
	Chanwoo Choi <cw00.choi@...sung.com>,
	Alexandre Belloni <alexandre.belloni@...tlin.com>,
	Linus Walleij <linus.walleij@...aro.org>,
	Bartosz Golaszewski <brgl@...ev.pl>, linux-gpio@...r.kernel.org,
	linux-rtc@...r.kernel.org, linux-kernel@...r.kernel.org,
	Thierry Reding <treding@...dia.com>
Subject: Re: [BUG] 6.16-rc7: lockdep failure with max77620-gpio/max77686-rtc

On Thu, Jul 31, 2025 at 01:18:19PM +0100, Russell King (Oracle) wrote:

> I can't see that anything has changed in the code with regards to the
> locking, so I think this is a bug that's been present ever since these
> drivers were introduced, and regmap-irq is deficient in that it causes
> the same lockdep lock class to be taken recursively when the IRQ wake
> state changes.

> From what I can see, irq wake support for regmap-irq was added in
> commit a43fd50dc99a5 ("regmap: Implement support for wake IRQs") and
> this is the only operation that is propagated to the parent
> interupt(s). Thus, the above splat is unlikely to occur unless one
> makes use of wake support on a regmap-irq based interrupt whose
> parent is also regmap-irq based.

Yes, your analysis is right here - it's not come up before because it's
very rare to chain regmap-irq chips.

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