From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [78.32.30.218]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 41F59227B88; Thu, 31 Jul 2025 19:21:04 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=78.32.30.218 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753989666; cv=none; b=GUYlTndlbuz5JC7VFI9l+hF7uJWs4PV5ApLnIyXKPnX8b/di2rNetZ92EaIA6G+R7LdR32rf51Xfje0c341XFj+q6fUT57EFx/yCOopQIY8Q/F0WQXu3x9luWx5v00AGhhFyGJmHtmTVW7eo51q4aDu8uWz4bDV780ZRvcU8sJM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1753989666; c=relaxed/simple; bh=hlW84O5IXieFS3BAA6oJjGjVOZOndCaF2/MOBTy7hRk=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=hyHzvoBypYEOhZVjQo0fIdt+q+ZMVPU5y1smqjhgGiTlArZ8Q9Vz5biXKA/vPkN13bTy90yzlLfV0R99wBZxNq/IOIbnRB55Ac37RJZaWY09vQYwab8WVMyWxOLGPjjlKrH31Boa97BkirhVECGA8kNpGiZpZ6Av51Xp0g2yrAU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=armlinux.org.uk; spf=none smtp.mailfrom=armlinux.org.uk; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b=HVBZEKp5; arc=none smtp.client-ip=78.32.30.218 Authentication-Results: smtp.subspace.kernel.org; dmarc=pass (p=none dis=none) header.from=armlinux.org.uk Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=armlinux.org.uk Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="HVBZEKp5" DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date:Reply-To: Content-Transfer-Encoding:Content-ID:Content-Description:Resent-Date: Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID:List-Id: List-Help:List-Unsubscribe:List-Subscribe:List-Post:List-Owner:List-Archive; bh=LDKoQUIZJ5jfnmQIpnLfj7b5yKy8PpiGA3COb32mcFQ=; b=HVBZEKp5s/9aVsNeTvkiNnPFbE OVg8M8PYEL+tXmOUZJix5a5ksf9W1BGhV9/UQxjonNBp9tykDR7NW6F1+8TMvFkSJH3Bp6ukV/5Nl MkiFXv1xNv2RElxmun2ggM79S2wAmeOCCHCzkfIE3tY1YecSMPyt3OFYeK9Y8CXbq5PYv4/Mi8vVU S6qvRNUUMdQfT2eOBA0+RTc1dFJe27H0dWjtlp042ytEtqYCdHG8sazufDpjE1WtqpqL64kuNcHrU xbUoK4GSWYQ4/Hjheia09/0/sMoY2h/+KlqfAM83WuJqkxNEu3f+eV4vjTlnWOVP6dwyLDpIYW8Zn RgiaYvCA==; Received: from shell.armlinux.org.uk ([fd8f:7570:feb6:1:5054:ff:fe00:4ec]:43254) by pandora.armlinux.org.uk with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.96) (envelope-from ) id 1uhYpj-0005QI-1u; Thu, 31 Jul 2025 20:20:55 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.96) (envelope-from ) id 1uhYpg-0001HB-03; Thu, 31 Jul 2025 20:20:52 +0100 Date: Thu, 31 Jul 2025 20:20:51 +0100 From: "Russell King (Oracle)" To: Mark Brown Cc: Krzysztof Kozlowski , Chanwoo Choi , Alexandre Belloni , Linus Walleij , Bartosz Golaszewski , linux-gpio@vger.kernel.org, linux-rtc@vger.kernel.org, linux-kernel@vger.kernel.org, Thierry Reding Subject: Re: [BUG] 6.16-rc7: lockdep failure with max77620-gpio/max77686-rtc Message-ID: References: <97f0e27f-3128-4821-bc09-2acde1ebf81a@kernel.org> <68c210a2-49b2-4fd2-97ad-27af85369d9f@sirena.org.uk> <4f80be02-0bbe-4c10-a3d2-324916ea2ca4@sirena.org.uk> <14c68c29-68d8-4119-8f70-616c07397dc4@sirena.org.uk> Precedence: bulk X-Mailing-List: linux-gpio@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: Russell King (Oracle) On Thu, Jul 31, 2025 at 06:03:43PM +0100, Mark Brown wrote: > On Thu, Jul 31, 2025 at 05:28:39PM +0100, Russell King (Oracle) wrote: > > On Thu, Jul 31, 2025 at 05:16:13PM +0100, Mark Brown wrote: > > > > Yeah, and that's all internals which we're not super encouraged to peer > > > at. There should be something that'll give us a nesting level > > > somewhere... > > > > Lockdep's handling of nesting is generally fun. > > > As I said, I'm just going to disable lockdep to shut up the warning and > > not pursue any further time on this. If someone else cares about it > > (which I doubt) they can try to come up with a solution. I suspect > > nested regmap-irq is extremely rare. > > I'm pretty sure it's extremely rare, and I'll have to construct a > virtual setup to actually test. After poking at it some more I think > we're actually going to need an explicit lock_class_key for each > regmap-irq rather than relying on the default lockdep one. I'll try to > send out a patch for that today or tomorrow but likely not really tested > - if you could find time to give it a spin on the affected system that'd > be good, but if not no worries. Thanks for the report and analysis. I hope we don't have too many regmap-irq's in a system - see the section on "Troubleshooting" in the lockdep documentation. There's a limit on the numbe of classes over the entire kernel. For reference, on the platform which provokes this lockdep splat, we already have 1518 lock classes: # grep "lock-classes" /proc/lockdep_stats lock-classes: 1518 [max: 8192] As I understand from the documentation, lock classes are create-only, there's no way of "freeing" them later, so we better not get into a situation where the number of classes steadily increase while the system is running! -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTP is here! 80Mbps down 10Mbps up. Decent connectivity at last!