Re: [PATCH] ARM: exynos_defconfig: Enable big.LITTLE CPUidle support

[Javier Martinez Canillas]

Hello Krzysztof,

On 08/29/2015 11:01 AM, Krzysztof Kozlowski wrote:
> W dniu 28.08.2015 o 17:16, Javier Martinez Canillas pisze:
>> Some Exynos big.LITTLE boards (i.e: Exynos5420 and Exynos5800 based
>> Chromebooks) have proper firmware that allow the big.LITTLE CPUidle
>> driver to work correctly, so enable support for this.
>>
>> Signed-off-by: Javier Martinez Canillas <javier@xxxxxxxxxxxxxxx>
>>
>> ---
>> Kukjin and Krzysztof,
>>
>> As you know there are other boards like the Exynos5422 based Odroid XU{3,4}
>> whose firmware is broken due leaving CCI in secure mode which means that the
>> kernel MCPM support can't properly manage CCI.
>>
>> So if you pick this patch, it should be tested in kernelci before appearing
>> in linux-next to prevent any boot issues.
>>
>> But if that happens, I believe that is better to do a fix / workaround in
>> those broken platforms since nothing prevents users to enable this option
>> anyways. For example the CCI device node could be disabled in the DTS.
>>
>>  arch/arm/configs/exynos_defconfig | 1 +
>>  1 file changed, 1 insertion(+)
> 
> On Odroid XU3L (next-20150828, Hardkernel u-boot) boot hangs just after:
>

Thanks for testing, I was expecting that is just that I don't have a
Odroid XU{3,4} board for test here, I guess I should get one.
 
> [    2.568650] dwmmc_exynos 12200000.mmc: num-slots property not found,
> assuming 1 slot is available
> 
> ... so no. NACK :). First the boards, firmware, bootloader or kernel

Agreed with the nack :)

> code have to be fixed.
>

Or disable CCI, could you please test the following patch [0] so I
can post it properly?
 
> Best regards,
> Krzysztof
> 

Best regards,
-- 
Javier Martinez Canillas
Open Source Group
Samsung Research America

[0]: