From: Florian Fainelli <florian.fainelli@broadcom.com>
To: Marc Zyngier <maz@kernel.org>,
linux-kernel@vger.kernel.org,
linux-arm-kernel@lists.infradead.org
Cc: John <therealgraysky@proton.me>,
Daniel Drake <dan@reactivated.net>,
Marek Szyprowski <m.szyprowski@samsung.com>,
Daniel Lezcano <daniel.lezcano@linaro.org>,
Thomas Gleixner <tglx@linutronix.de>,
Mark Rutland <mark.rutland@arm.com>
Subject: Re: [PATCH] clocksource/drivers/arm_arch_timer: Workaround bcm2712 broken EL2 virtual timer
Date: Mon, 13 Jul 2026 09:15:35 -0700 [thread overview]
Message-ID: <1c23b437-609c-470a-8b14-34288cb5aaa3@broadcom.com> (raw)
In-Reply-To: <20260710080958.491620-1-maz@kernel.org>
On 7/10/26 01:09, Marc Zyngier wrote:
> It appears that the bcm2712 SoC found in the relatively popular
> RPi5 has a broken EL2 virtual timer.
>
> We do not know the reason why the timer isn't working (the timer
> is ticking, but the interrupt never fires), and the SoC vendor
> doesn't communicate on the reason why this isn't working, leaving
> users and maintainers in the dark.
>
> Paper over the issue by detecting the broken HW, falling back to
> the physical timer instead, and let the user know about it.
> Also taint the kernel as the machine is definitely not compliant
> with the spec, and we don't know what else is wrong with it.
>
> Reported-by: John <therealgraysky@proton.me>
> Reported-by: Daniel Drake <dan@reactivated.net>
> Reported-by: Marek Szyprowski <m.szyprowski@samsung.com>
> Signed-off-by: Marc Zyngier <maz@kernel.org>
> Cc: Florian Fainelli <florian.fainelli@broadcom.com>
> Cc: Daniel Lezcano <daniel.lezcano@linaro.org>
> Cc: Thomas Gleixner <tglx@linutronix.de>
> Cc: Mark Rutland <mark.rutland@arm.com>
Acked-by: Florian Fainelli <florian.fainelli@broadcom.com>
We know why now: the virtual interrupt timer line was never connected in
the first place because it was not clarified that it was a requirement.
I will also take the DTS patch through the Broadcom ARM SoC tree.
Thanks!
--
Florian
next prev parent reply other threads:[~2026-07-13 16:15 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-10 8:09 [PATCH] clocksource/drivers/arm_arch_timer: Workaround bcm2712 broken EL2 virtual timer Marc Zyngier
2026-07-13 16:15 ` Florian Fainelli [this message]
2026-07-13 20:23 ` Marc Zyngier
2026-07-13 22:38 ` Florian Fainelli
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