Functional testing of mainline vchiq driver

[Stefan Wahren]

> Phil Elwell <phil at raspberrypi.org> hat am 31. Oktober 2016 um 11:28
> geschrieben:
> 
> 
> On 31/10/2016 10:21, Stefan Wahren wrote:
> >
> >> Michael Zoran <mzoran at crowfest.net> hat am 30. Oktober 2016 um 18:00
> >> geschrieben:
> >>
> >> Going back to the cache line size issue.  
> >>
> >> I'm wondering if it's important to people to not have an override, if
> >> it would just make sense to use a reasonably large value in the DT that
> >> works on all the platforms.  Say 64 or 128.  I mean, I think the line
> >> size is sent over to the firmware in the driver init so making the
> >> number too big is just a performance issue and not a correctness issue,
> >> right?
> >>
> > If i change g_cache_line_size to 64 on a Raspberry Pi B then i get this:
> >
> > $ vchiq_test -f 10
> > Functional test - iters:10
> > ======== iteration 1 ========
> > vchiq_test: 1: Data corrupted at 0-0 (datalen 1, align fe0, server_align 0)
> > ->
> > 80
> > vchiq_test: 891: func_data_test(service, size, PAGE_SIZE - align, srvr_align
> > &
> > 31) != VCHIQ_SUCCESS
> 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?