Re: [Xen-devel] ARM: EXYNOS 5410 - DOM0 not being scheduled

[Julien Grall <julien.grall@xxxxxxxxxx>]

Hi Ian,

On 03/18/2014 09:52 AM, Ian Campbell wrote:
> On Mon, 2014-03-17 at 22:15 +0000, Julien Grall wrote:
>>> 2. arch_timer_rate coming up as 0 in dom0 inspite of the dtb defining
>>> clock-frequency.
>>
>> The clock-frequency properties is not given to dom0. It should be able 
>> to retrieve the frequency from the timer (CNTFRQ). That would mean that 
>> u-boot is not correctly set up the frequency (it's the only one able to 
>> do it as it need to be done in secure world).
> 
> If the clock-frequency property is present in the host DT then that
> would imply that secure world is not setting CNTFRQ or is setting it
> wrong (since the property is effectively a workaround for that exact
> bug). Perhaps we should propagate it if it is present?

It's easy to do it for dom0, what about guests? I think it would be
better to let the bootloader to set up the frequency. I'm a bit
surprised that it's not already the case for this board.

For instance, on the Arndale the property "clock-frequency" exists but
CNTFRQ is also correctly set.

> While grepping about this I noticed that make_timer_node doesn't use
> DT_MATCH_TIMER, which I guess is just an accidental oversight, perhaps
> if someone is fixing the clock-frequency issue they could throw in a
> second patch for this too?

I think it's an error during the cleanup.

Regards,

-- 
Julien Grall

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