From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-alma10-1.taild15c8.ts.net [100.103.45.18]) (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 A652F3EB801; Fri, 10 Jul 2026 08:12:14 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=100.103.45.18 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783671136; cv=none; b=jH5P7/bM2OTHUg8ptw9AV+8Zdy8wslaQXcrKqwV1Dwg6q+nAczoEGCimmwvsl02bqsTd5bFtoCf9VXgSPC10/Lz1QLaVpaDC7c0KLs47tz9NtRFP7F0ZjksUU5kdzYGaMnq1VuHJpEDA5RzJeVXBRr+L0xMrQGqUCt0oinCR0y4= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1783671136; c=relaxed/simple; bh=EGXmBFOFGPJRCa2KDW3qx68vLK9mF6Uj/kcuDfPy0IQ=; h=Date:Message-ID:From:To:Cc:Subject:In-Reply-To:References: MIME-Version:Content-Type; b=T/z65PlXGpEuW+LIX5sVmTsT0XuxaihWeRSNZf73bm7VTP/hIh+uOCUIBgbt5HWchR9zCHA0JvSrLDxcQLhkJTsAQc9J7AYN3zDm7zTu3NLYqhxJe+0psyElCcMX2FhvhX4LuSsyuN+pxkgOLjQl/us1/K3wHzutrRzo+HbPp/8= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=BP4bd7W6; arc=none smtp.client-ip=100.103.45.18 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="BP4bd7W6" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 7D23D1F000E9; Fri, 10 Jul 2026 08:12:13 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=kernel.org; s=k20260515; t=1783671133; bh=h7nDO43+tKnnu6CxuyKnxlviLmUXS03CPGd8nFXhdng=; h=Date:From:To:Cc:Subject:In-Reply-To:References; b=BP4bd7W6zNBoI3b8Ib5OZzb2TuuQl527kyh0lxT5H1eBurLMsZ17mx8X+/cD2lq/d D0PxqKmKSLjAiJTw5dBDbP4hjTSfU96lNIKZsD8HrgnmKxutHHtVASVcAQ/vUpEK6M cmDIFWwvV90wXoP9v3rQtXBuiXDWk3InlVaJGYuJBXgSykJS4V2gcx3kN8320jPG3Q yA5nWSurT6o/nvIIUXnqKo1+Yh0UXlO9kqujC5ap1uXeZHKpEQSqhyFyPuCzXPfgLt GJBWWFxIalOsLx8gE31Eww9QE8SP2mQDXOR2SfTleQNXdLSqNNxAjodwDJOfrpDK6b BFgkuoDzxpxVQ== Received: from sofa.misterjones.org ([185.219.108.64] helo=lobster-girl.misterjones.org) by disco-boy.misterjones.org with esmtpsa (TLS1.3) tls TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384 (Exim 4.98.2) (envelope-from ) id 1wi6LD-00000003aiN-2BIe; Fri, 10 Jul 2026 08:12:11 +0000 Date: Fri, 10 Jul 2026 09:14:00 +0100 Message-ID: <87tsq75kjb.wl-maz@kernel.org> From: Marc Zyngier To: John Cc: Mark Rutland , Daniel Lezcano , Thomas Gleixner , Rob Herring , Krzysztof Kozlowski , Conor Dooley , Florian Fainelli , Broadcom internal kernel review list , "Ivan T. Ivanov" , Stefan Wahren , Andrea della Porta , Peter Robinson , Stanimir Varbanov , =?UTF-8?B?TWHDrXJh?= Canal , Gregor Herburger , "linux-arm-kernel@lists.infradead.org" , "linux-kernel@vger.kernel.org" , "devicetree@vger.kernel.org" , "linux-rpi-kernel@lists.infradead.org" Subject: Re: [REGRESSION] Raspberry Pi 5 (BCM2712) hangs at boot since d87773de9efe (arm_arch_timer: default to EL2 virtual timer under VHE) In-Reply-To: References: <86h5mcp4em.wl-maz@kernel.org> User-Agent: Wanderlust/2.15.9 (Almost Unreal) SEMI-EPG/1.14.7 (Harue) FLIM-LB/1.14.9 (=?UTF-8?B?R29qxY0=?=) APEL-LB/10.8 EasyPG/1.0.0 Emacs/30.1 (aarch64-unknown-linux-gnu) MULE/6.0 (HANACHIRUSATO) Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 (generated by SEMI-EPG 1.14.7 - "Harue") Content-Type: text/plain; charset=US-ASCII X-SA-Exim-Connect-IP: 185.219.108.64 X-SA-Exim-Rcpt-To: therealgraysky@proton.me, mark.rutland@arm.com, daniel.lezcano@kernel.org, tglx@kernel.org, robh@kernel.org, krzk+dt@kernel.org, conor+dt@kernel.org, florian.fainelli@broadcom.com, bcm-kernel-feedback-list@broadcom.com, iivanov@suse.de, wahrenst@gmx.net, andrea.porta@suse.com, pbrobinson@gmail.com, svarbanov@suse.de, mcanal@igalia.com, gregor.herburger@linutronix.de, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, devicetree@vger.kernel.org, linux-rpi-kernel@lists.infradead.org X-SA-Exim-Mail-From: maz@kernel.org X-SA-Exim-Scanned: No (on disco-boy.misterjones.org); SAEximRunCond expanded to false On Mon, 06 Jul 2026 16:20:13 +0100, John wrote: > > On Monday, July 6th, 2026 at 10:40 AM, Marc Zyngier wrote: > > > On Mon, 06 Jul 2026 15:13:27 +0100, > > John wrote: > > > > > > Since commit d87773de9efe ("clocksource/drivers/arm_arch_timer: Default to EL2 virtual timer when running VHE"), the Raspberry Pi 5 (BCM2712, arm64) hangs during boot on v7.2-rc1 and later. Reverting that commit on top of v7.2-rc2 boots reliably. Found by bisection. > > > > > > Environment: - Raspberry Pi 5 Model B, arm64, device-tree boot (no ACPI) - CPUs start at EL2 with VHE - Mainline v7.2-rc1 and v7.2-rc2 > > > > > > Symptom: - Silent hang early in driver probe; no panic or oops. Boot banner shows > > > "arch_timer: cp15 timer running at 54.00MHz (hyp-virt)". The first blocking, timer-backed wait during probe never returns because the EL2 virtual timer's interrupt is not delivered on this SoC, so clockevents are dead. The softlockup/hung-task detectors can't fire either, since they depend on the same dead timer. > > > > > > > Is that a guess? Or do you know something we don't? Or worse, is this > > report entirely AI generated? > > Hi Marc - I'm not a programmer, but I can use git. I performed the bisect, and verification steps by hand. I am convinced the bisect is correct based on the restoration of booting. > > My RPi5B freezes when booting into d87773de9e and reverting it gives a clean boot. > > I used Opus to analyze the result of the bisect in concert with the logs I captured from the serial console. I also used it to summarize everything into a concise bug report. I can't vouch for the accuracy of the interpretation, but I can confirm the problematic commit and restoration of function. > > > > Again, how do you know it isn't functional? Could it be, for example, > > that the firmware has not configured the interrupt correctly? > > I cannot. In the future, when I use these tools, I will scope the ask to just factual content, rather than allowing them to speculate. > > > A proposed fix has been posted at [1]. Until we hear from the > > implementer about the state of the HW, it is difficult to do anything. > > > > M. > > > > [1] https://lore.kernel.org/all/878q898ulx.wl-maz@kernel.org/ > > Thank you for linking that! I applied it on top of 7.2-rc2 (with d87773de9efe intact) and got a clean boot. FWIW, and in the absence of any feedback from the SoC manufacturer, I've posted this patch[2]. There isn't much else I can do for this stuff. M. [2] https://lore.kernel.org/all/20260710080958.491620-1-maz@kernel.org/ -- Jazz isn't dead. It just smells funny.