[Nouveau] [RFC PATCH] gr: did you try turning it off and on again.

[Tobias Klausmann]

Hi,

comments inline

On 11/28/17 2:11 PM, Karol Herbst wrote:
> Fixes secure boot on my gp107. No idea why. Otherwise the GPU enters
> complete lockdown after starting the gpccs and fecs with the LS images
> loaded.
>
> Signed-off-by: Karol Herbst <kherbst at redhat.com>
> ---
>   drm/nouveau/nvkm/engine/gr/gf100.c | 7 +++++++
>   1 file changed, 7 insertions(+)
>
> diff --git a/drm/nouveau/nvkm/engine/gr/gf100.c b/drm/nouveau/nvkm/engine/gr/gf100.c
> index 2f8dc107..322d9fa6 100644
> --- a/drm/nouveau/nvkm/engine/gr/gf100.c
> +++ b/drm/nouveau/nvkm/engine/gr/gf100.c
> @@ -1731,8 +1731,15 @@ gf100_gr_init_(struct nvkm_gr *base)
>   {
>   	struct gf100_gr *gr = gf100_gr(base);
>   	struct nvkm_subdev *subdev = &base->engine.subdev;
> +	struct nvkm_device *device = subdev->device;
>   	u32 ret;
>   
> +	/* did you try turning it off and on again? Apparently we need this
> +	 * on pascal, otherwise secboot will just fail.


The comments about the off and on looks silly, at least put it in 
quotation marks, or rewrite it, e.g. "Apparently we need to turn it off 
and on for the pascal generation, otherwise secboot will just fail."

> +	 */
> +	nvkm_mask(device, 0x200, 0x1000, 0x0000);
> +	nvkm_mask(device, 0x200, 0x1000, 0x1000);
> +


It is needed with pascal, but does it harm other generations calling 
this init? Maybe guard it against exectution on maxwell


Greetings,

Tobias


>   	nvkm_pmu_pgob(gr->base.engine.subdev.device->pmu, false);
>   
>   	ret = nvkm_falcon_get(gr->fecs, subdev);