[PATCH 0/2] ARM: EXYNOS: Allow to use architected timer

Alexey Klimov klimov.linux at gmail.com
Tue Oct 6 01:51:50 PDT 2015


(add linux-samsung-soc mail list to cc)

On Tue, Oct 6, 2015 at 11:37 AM, Arnd Bergmann <arnd at arndb.de> wrote:
> On Tuesday 06 October 2015 11:23:58 Pavel Fedin wrote:
>> Exynos platform officially uses "multi-core timer" AKA MCT. However, it
>> also has a possibility to access the same timer using CP15 (AKA
>> architected timer) registers.
>>
>> In order to be able to use KVM, we need CP15 timer support. In its turn,
>> MCT needs to be turned on before any accesses will work. This patchset
>> allows to specify "CP15 compatibility mode" for the MCT by inserting
>> armv7-timer node as a child for MCT device. In this case MCT driver will
>> only enable the timer, leaving the rest for architected timer driver.
>
> IIRC the use of the CP15 timer is not reliable on this platform.
> I don't have a link ready, but this has come up a few times.
>
> Kukjin Kim probably knows the details.

Please take a look: http://www.gossamer-threads.com/lists/linux/kernel/2225900
for some details. I don't know if it's related to 5410.

Best regards,
Alexey Klimov



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