Re: [PATCH] clocksource/drivers/arm_arch_timer: Workaround bcm2712 broken EL2 virtual timer

[Florian Fainelli]

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@xxxxxxxxx>
> Reported-by: Daniel Drake <dan@xxxxxxxxxxxxxxx>
> Reported-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> Signed-off-by: Marc Zyngier <maz@xxxxxxxxxx>
> Cc: Florian Fainelli <florian.fainelli@xxxxxxxxxxxx>
> Cc: Daniel Lezcano <daniel.lezcano@xxxxxxxxxx>
> Cc: Thomas Gleixner <tglx@xxxxxxxxxxxxx>
> Cc: Mark Rutland <mark.rutland@xxxxxxx>

Acked-by: Florian Fainelli <florian.fainelli@xxxxxxxxxxxx>

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