[Freedreno] Whether A200 driver is supported by Linux Mainline Kernel

[Wladimir J. van der Laan]

Hello Abhijit,

On Thu, Aug 10, 2017 at 07:45:03PM +0530, abhijit wrote:
> Hi Wladimir,
> 
> Thank you very much for the reply.
> 
> I am able to build the kernel, drm and mesa components.
> 
> After loading the kernel, I am getting following entries,
> 	/dev/gsl_kmod
> 	/dev/dri/card0
> 	/dev/dri/renderD128
> 

That's expected. gsl_kmod is for the GPU, card0/renderD128 is the
i.mx5x IPU/scanout.

> Can you please let me know what are the test application that be used to
> test the driver through gsl_kmod interface?

Anything using kms/gbm should work.

> Now to test the driver, I am running kmscube, which is giving exception,
>   "@MF@ using DRM kernel interface
>    @MF@ fd_device_del refcnt=1
>    @MF@ fd_device_del_impl
>    @MF@ fd_cleanup_bo_cache devtime=0 time=0 num_buckets=55
>    Segmentation fault"

you need:
export FD_DRM_USE_KGSL=1

> Can freedreno test be used with gsl_kmod interface, I am simultaneously
> trying build freedreno tests?

I don't know. Might well be that they depend on a msm interface to the kernel.

> I have allocated 9MB of memory to "memchunk" in
> drivers/mxc/amd-gpu/platform/hal/linux/gsl_hal.c as, dma_alloc_coherent is
> failing for 72MB

I set CONFIG_CMA_SIZE_MBYTES=128 to avoid that issue.
9MB of video memory is not enough, in any case.
and mmu is currently forced to disabled in the amdgpu driver as it resulted in crashes.
(this is something that broke during forward-porting it from the 2.x to 3.x kernel, unfortunately)

Regards,
Wladimir