[PATCH 2/6] drm/msm: gpu: Use the zap shader on 5XX if we can

[Jordan Crouse]

On Mon, Apr 17, 2017 at 12:58:07PM -0700, Bjorn Andersson wrote:
> On Wed 12 Apr 14:15 PDT 2017, Jordan Crouse wrote:
> > diff --git a/drivers/gpu/drm/msm/adreno/a5xx_gpu.c b/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
> > index 6c55d24..0e2b00a 100644
> > --- a/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
> > +++ b/drivers/gpu/drm/msm/adreno/a5xx_gpu.c
> > @@ -470,6 +470,55 @@ static int a5xx_ucode_init(struct msm_gpu *gpu)
> >  	return 0;
> >  }
> >  
> > +static int a5xx_zap_shader_resume(struct msm_gpu *gpu)
> > +{
> > +	int ret;
> > +
> > +	ret = qcom_scm_set_remote_state(0, 13);
> 
> Is 13 here the PAS_ID, or just a coincidence? And what is state 0? Can
> we have a define for this?

I think it is officially a coincidence but probably an informed one. Now that I
think about it I seem to remember Andy asking me to add a define for the 13.
The state is more confusing - because video is the other consumer of this call
and they call 0 to disable and 1 to enable, and GPU calls 0 to enable.  I can
add a #define but it will be just for GPU - maybe something like
REMOTE_STATE_GPU_RESUME?


> > +	if (ret)
> > +		DRM_ERROR("%s: zap-shader resume failed: %d\n",
> > +			gpu->name, ret);
> > +
> > +	return ret;
> > +}
> > +
> > +static int a5xx_zap_shader_init(struct msm_gpu *gpu)
> > +{
> > +	static bool loaded;
> > +	struct adreno_gpu *adreno_gpu = to_adreno_gpu(gpu);
> > +	struct a5xx_gpu *a5xx_gpu = to_a5xx_gpu(adreno_gpu);
> > +	struct platform_device *pdev = a5xx_gpu->pdev;
> > +	struct device_node *node;
> > +	int ret;
> > +
> > +	/*
> > +	 * If the zap shader is already loaded into memory we just need to kick
> > +	 * the remote processor to reinitialize it
> > +	 */
> > +	if (loaded)
> > +		return a5xx_zap_shader_resume(gpu);
> > +
> > +	/* Populate the sub-nodes if they haven't already been done */
> > +	of_platform_populate(pdev->dev.of_node, NULL, NULL, &pdev->dev);
> 
> As this is new code, there's little (no) value in doing this stepwise,
> just squash this with the later commits replacing this.

Yeah, I'm thinking I'll do a squash on the next go around unless Rob objects.

Jordan
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