Re: [PATCH v3] clocksource: exynos_mct: Increase priority over ARM arch timer
From: Daniel Lezcano
Date: Fri May 31 2019 - 10:54:32 EST
On 30/05/2019 12:50, Marek Szyprowski wrote:
> Exynos SoCs based on CA7/CA15 have 2 timer interfaces: custom Exynos MCT
> (Multi Core Timer) and standard ARM Architected Timers.
>
> There are use cases, where both timer interfaces are used simultanously.
> One of such examples is using Exynos MCT for the main system timer and
> ARM Architected Timers for the KVM and virtualized guests (KVM requires
> arch timers).
>
> Exynos Multi-Core Timer driver (exynos_mct) must be however started
> before ARM Architected Timers (arch_timer), because they both share some
> common hardware blocks (global system counter) and turning on MCT is
> needed to get ARM Architected Timer working properly.
>
> To ensure selecting Exynos MCT as the main system timer, increase MCT
> timer rating. To ensure proper starting order of both timers during
> suspend/resume cycle, increase MCT hotplug priority over ARM Archictected
> Timers.
>
> Signed-off-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> Reviewed-by: Krzysztof Kozlowski <krzk@xxxxxxxxxx>
> Reviewed-by: Chanwoo Choi <cw00.choi@xxxxxxxxxxx>
> ---
Applied thanks!
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