[PATCH] clocksource: arm_global_timer: Allow DT to specify already reset timer counter

Daniel Lezcano daniel.lezcano at linaro.org
Tue Dec 15 22:59:34 PST 2015


On 12/16/2015 05:11 AM, Jassi Brar wrote:
> On Tue, Dec 15, 2015 at 11:32 PM, Daniel Lezcano
> <daniel.lezcano at linaro.org> wrote:
>> On 11/25/2015 06:24 AM, Jassi Brar wrote:
>>>
>>> The GT counter is common to every core in a cluster. There is a usecase
>>> when Linux is spawned by a 'master' firmware/OS running on some core of
>>> the same cluster and the GT is used by the both.
>>>    Linux, upon boot, resetting the GT counter is obviously fatal to the
>>> other OS. So provide a way for DT to tell Linux if it's running in that
>>> 'slave' mode and must not reset the counter.
>>>
>>> Signed-off-by: Jassi Brar <jaswinder.singh at linaro.org>
>>
>>
>> Hmm, I doubt that is a hardware description.
>>
> Its a regular 2core-1cluster platform. The master RTOS on cpu0
> maintains the lifecycle of Linux on cpu1.
>
> 'No_Counter_Reset' is not a h/w thing, I agree, but I don't know how
> to better convey that platform specific constraint.

May be with a kernel parameter ?

-- 
  <http://www.linaro.org/> Linaro.org │ Open source software for ARM SoCs

Follow Linaro:  <http://www.facebook.com/pages/Linaro> Facebook |
<http://twitter.com/#!/linaroorg> Twitter |
<http://www.linaro.org/linaro-blog/> Blog




More information about the linux-arm-kernel mailing list