Functional testing of mainline vchiq driver

[Phil Elwell]

On 31/10/2016 12:10, Stefan Wahren wrote:
>> Phil Elwell <phil at raspberrypi.org> hat am 31. Oktober 2016 um 12:05
>> geschrieben:
>>
>>
>> On 31/10/2016 10:42, Stefan Wahren wrote:
>>> Phil Elwell <phil at raspberrypi.org> hat am 31. Oktober 2016 um
>>> 11:28geschrieben:
>>>> That's because the firmware doesn't read the cache line size value from
>>>> the DTB - it knows which chip it is running on, and hence the correct
>>>> value - so forcing an incorrect value for the ARM causes a discrepancy.
>>> In case VPU and ARM core need the same value i suggest to request the
>>> firmware
>>> about that.
>>> I assume there is no possibility to request the cache line size directly.
>>> So we need to decide based on something like RPI_FIRMWARE_GET_BOARD_MODEL?
>> The firmware already tells the ARM the correct value by ensuring it has
>> an appropriate DTB file. Are you really suggesting adding a method to
>> query at runtime a property of the hardware which cannot change?
>>
>> I thought Device Tree was meant to contain static device configuration
>> information like that. The fact that there isn't already a
>> cache-line-size property on the CPU nodes seems like an oversight.
>>
> Okay now the penny dropped. Forget about my suggestion.
>
> Sorry, one more question is it guaranteed that the VPU firmware finished writing
> to the Device Tree BEFORE the ARM core starts?
Yes.