Re: [RFC 17/24] xen/arm: Mark each device used by Xen as disabled in DOM0 FDT

[Julien Grall <julien.grall@linaro.org>]

On 08/22/2013 02:50 PM, Ian Campbell wrote:
> On Fri, 2013-08-16 at 22:05 +0100, Julien Grall wrote:
>> When a device has a property status with disabled inside, Linux will not use
>> the device.
> 
> Is Linux consistent about that?

For general device (ie: not GIC, timer, and malformed driver), yes.

I choose this solution because, I'm not sure how Linux react if, for
example, on a board with 3 UARTs, the second UART is removed.
Set status property to "disabled" works fine for me.

> I must admit I thought we omitted things in use by Xen from the DT
> altogether. Is that no longer true.

> 
>>
>> Signed-off-by: Julien Grall <julien.grall@linaro.org>
>> ---
>>  xen/arch/arm/domain_build.c |    8 ++++++++
>>  1 file changed, 8 insertions(+)
>>
>> diff --git a/xen/arch/arm/domain_build.c b/xen/arch/arm/domain_build.c
>> index c8f24ed..8377610 100644
>> --- a/xen/arch/arm/domain_build.c
>> +++ b/xen/arch/arm/domain_build.c
>> @@ -208,6 +208,14 @@ static int write_properties(struct domain *d, struct kernel_info *kinfo,
>>              return res;
>>      }
>>  
>> +    /* Disable all devices used by Xen */
>> +    if ( dt_device_used_by(np) == DOMID_XEN )
>> +    {
>> +        res = fdt_property(kinfo->fdt, "status", "disabled", 8 + 1);
>> +        if ( res )
>> +            return res;
>> +    }
>> +
>>      /*
>>       * XXX should populate /chosen/linux,initrd-{start,end} here if we
>>       * have module[2]
> 
> 


-- 
Julien Grall