Hi Mylène,
On 19/02/18 08:18, Mylène Josserand wrote:
> The ARM architected timers use an offset between their physical and
> virtual counters. That offset should be configured by the bootloader
> in CNTVOFF.
>
> However, the A83t bootloader fails to do so, and we end up with an
> undefined offset (which in our case is random), meaning that each CPU
> will have a different time, which isn't working very well.
>
> Fix that by setting the arm,cpu-registers-not-fw-configured that will
> make Linux use the physical timers instead of the virtual ones. One
> possible side effect would be that the virtualization features would
> be disabled. However, due to the way the GIC has been integrated in
> the system, it is already unusable so we're effectively not losing any
> feature.
>
> Signed-off-by: Mylène Josserand <mylene.josserand@xxxxxxxxxxx>
> ---
> arch/arm/boot/dts/sun8i-a83t.dtsi | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/arch/arm/boot/dts/sun8i-a83t.dtsi b/arch/arm/boot/dts/sun8i-a83t.dtsi
> index e97a6d17b8d0..b9bdb891cf2f 100644
> --- a/arch/arm/boot/dts/sun8i-a83t.dtsi
> +++ b/arch/arm/boot/dts/sun8i-a83t.dtsi
> @@ -123,6 +123,7 @@
> <GIC_PPI 14 (GIC_CPU_MASK_SIMPLE(8) | IRQ_TYPE_LEVEL_LOW)>,
> <GIC_PPI 11 (GIC_CPU_MASK_SIMPLE(8) | IRQ_TYPE_LEVEL_LOW)>,
> <GIC_PPI 10 (GIC_CPU_MASK_SIMPLE(8) | IRQ_TYPE_LEVEL_LOW)>;
> + arm,cpu-registers-not-fw-configured;
> };
>
> clocks {
>
Is the firmware dropping you in the kernel in secure or non-secure mode?
If the later, what you have is the only solution. If the former, that
I'd suggest you adopt what we already have for the Renesas stuff (see
arch/arm/mach-shmobile/headsmp-apmu.S and commit 3fd45a136ff6).
It would allow you to use the virtual timer as intended.
Thanks,
M.
--
Jazz is not dead. It just smells funny...
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