Re: [Xen-devel] [PATCH v2] xen/arm: Propagate clock-frequency to DOMU if present in the DT timer node

[Ian Campbell <ian.campbell@xxxxxxxxxx>]

On Fri, 2015-06-19 at 13:41 +0100, Julien Grall wrote:
> When the property "clock-frequency" is present in the DT timer node, it
> means that the bootloader/firmware didn't correctly configure the
> CNTFRQ/CNTFRQ_EL0 on each processor.
> 
> The best solution would be to fix the offending firmware/bootloader,
> although it may not always be possible to modify and re-flash it.
> 
> As it's not possible to trap the register CNTFRQ/CNTFRQ_EL0, we have
> to extend xen_arch_domainconfig to provide the timer frequency to the
> toolstack when the property "clock-frequency" is present to the host DT
> timer node. Then, a property "clock-frequency" will be created in the guest
> DT timer node if the value is not 0.
> 
> We could have set the property in the guest DT no matter if the property
> is present in the host DT. Although, we still want to let the guest
> using CNTFRQ in normal case. After all, the property "clock-frequency"
> is just a workaround for buggy firmware.
> 
> Also add a stub for fdt_property_u32 which is not present in libfdt <
> 1.4.0 used by distribution such as Debian Wheezy.
> 
> Signed-off-by: Julien Grall <julien.grall@xxxxxxxxxx>
> Tested-by: Chris Brand <chris.brand@xxxxxxxxxxxx>

Acked + applied, thanks

>     This patch requires to regenerate tools/configure.

Done.



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