Re: [PATCH 2/2] drm/msm: Fix duplicate gpu node in icc summary

[Jordan Crouse <jcrouse@codeaurora.org>]

On Mon, Oct 19, 2020 at 06:49:18PM +0530, Akhil P Oommen wrote:
> On targets with a6xx gpu, there is a duplicate gpu icc node listed in
> the interconnect summary. On these targets, calling

This first sentence is confusing to me. I think the following few sentences do
a better job of explaining what you are trying to do.

> dev_pm_opp_of_add_table() api initializes the icc nodes for gpu indirectly.
> So we should avoid using of_icc_get() api in the common probe path. To fix
> this, we can move of_icc_get() to target specific code where it is
> required.

> Signed-off-by: Akhil P Oommen <akhilpo@codeaurora.org>
> ---
>  drivers/gpu/drm/msm/adreno/a3xx_gpu.c   | 21 +++++++++++++++++++--
>  drivers/gpu/drm/msm/adreno/a4xx_gpu.c   | 20 ++++++++++++++++++--
>  drivers/gpu/drm/msm/adreno/adreno_gpu.c | 29 +----------------------------
>  3 files changed, 38 insertions(+), 32 deletions(-)
> 
> diff --git a/drivers/gpu/drm/msm/adreno/a3xx_gpu.c b/drivers/gpu/drm/msm/adreno/a3xx_gpu.c
> index f29c77d..93da668 100644
> --- a/drivers/gpu/drm/msm/adreno/a3xx_gpu.c
> +++ b/drivers/gpu/drm/msm/adreno/a3xx_gpu.c
> @@ -519,6 +519,8 @@ struct msm_gpu *a3xx_gpu_init(struct drm_device *dev)
>  	struct msm_gpu *gpu;
>  	struct msm_drm_private *priv = dev->dev_private;
>  	struct platform_device *pdev = priv->gpu_pdev;
> +	struct icc_path *ocmem_icc_path;
> +	struct icc_path *icc_path;
>  	int ret;
>  
>  	if (!pdev) {
> @@ -566,13 +568,28 @@ struct msm_gpu *a3xx_gpu_init(struct drm_device *dev)
>  		goto fail;
>  	}
>  
> +	icc_path = devm_of_icc_get(&pdev->dev, "gfx-mem");
> +	ret = IS_ERR(icc_path);
> +	if (ret)
> +		goto fail;
> +
> +	ocmem_icc_path = devm_of_icc_get(&pdev->dev, "ocmem");
> +	ret = IS_ERR(ocmem_icc_path);
> +	if (ret) {
> +		/* allow -ENODATA, ocmem icc is optional */
> +		if (ret != -ENODATA)
> +			goto fail;
> +		ocmem_icc_path = NULL;
> +	}
> +
> +
>  	/*
>  	 * Set the ICC path to maximum speed for now by multiplying the fastest
>  	 * frequency by the bus width (8). We'll want to scale this later on to
>  	 * improve battery life.
>  	 */
> -	icc_set_bw(gpu->icc_path, 0, Bps_to_icc(gpu->fast_rate) * 8);
> -	icc_set_bw(gpu->ocmem_icc_path, 0, Bps_to_icc(gpu->fast_rate) * 8);
> +	icc_set_bw(icc_path, 0, Bps_to_icc(gpu->fast_rate) * 8);
> +	icc_set_bw(ocmem_icc_path, 0, Bps_to_icc(gpu->fast_rate) * 8);

This seems reasonable but I hope we can get somebody to sign off on a real a3xx
part.

>  
>  	return gpu;
>  
> diff --git a/drivers/gpu/drm/msm/adreno/a4xx_gpu.c b/drivers/gpu/drm/msm/adreno/a4xx_gpu.c
> index 2b93b33..c0be3a0 100644
> --- a/drivers/gpu/drm/msm/adreno/a4xx_gpu.c
> +++ b/drivers/gpu/drm/msm/adreno/a4xx_gpu.c
> @@ -648,6 +648,8 @@ struct msm_gpu *a4xx_gpu_init(struct drm_device *dev)
>  	struct msm_gpu *gpu;
>  	struct msm_drm_private *priv = dev->dev_private;
>  	struct platform_device *pdev = priv->gpu_pdev;
> +	struct icc_path *ocmem_icc_path;
> +	struct icc_path *icc_path;
>  	int ret;
>  
>  	if (!pdev) {
> @@ -694,13 +696,27 @@ struct msm_gpu *a4xx_gpu_init(struct drm_device *dev)
>  		goto fail;
>  	}
>  
> +	icc_path = devm_of_icc_get(&pdev->dev, "gfx-mem");
> +	ret = IS_ERR(icc_path);
> +	if (ret)
> +		goto fail;
> +
> +	ocmem_icc_path = devm_of_icc_get(&pdev->dev, "ocmem");
> +	ret = IS_ERR(ocmem_icc_path);
> +	if (ret) {
> +		/* allow -ENODATA, ocmem icc is optional */
> +		if (ret != -ENODATA)
> +			goto fail;
> +		ocmem_icc_path = NULL;
> +	}
> +
>  	/*
>  	 * Set the ICC path to maximum speed for now by multiplying the fastest
>  	 * frequency by the bus width (8). We'll want to scale this later on to
>  	 * improve battery life.
>  	 */
> -	icc_set_bw(gpu->icc_path, 0, Bps_to_icc(gpu->fast_rate) * 8);
> -	icc_set_bw(gpu->ocmem_icc_path, 0, Bps_to_icc(gpu->fast_rate) * 8);
> +	icc_set_bw(icc_path, 0, Bps_to_icc(gpu->fast_rate) * 8);
> +	icc_set_bw(ocmem_icc_path, 0, Bps_to_icc(gpu->fast_rate) * 8);

Less confident we can find any 4xx fans to test this, but if a3xx works then so
should this (in theory).

>  	return gpu;
>  
> diff --git a/drivers/gpu/drm/msm/adreno/adreno_gpu.c b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
> index fd8f491..6e3b820 100644
> --- a/drivers/gpu/drm/msm/adreno/adreno_gpu.c
> +++ b/drivers/gpu/drm/msm/adreno/adreno_gpu.c
> @@ -920,35 +920,8 @@ int adreno_gpu_init(struct drm_device *drm, struct platform_device *pdev,
>  
>  	ret = msm_gpu_init(drm, pdev, &adreno_gpu->base, &funcs->base,
>  			adreno_gpu->info->name, &adreno_gpu_config);
> -	if (ret)
> -		return ret;
> -
> -	/*
> -	 * The legacy case, before "interconnect-names", only has a
> -	 * single interconnect path which is equivalent to "gfx-mem"
> -	 */
> -	if (!of_find_property(dev->of_node, "interconnect-names", NULL)) {
> -		gpu->icc_path = of_icc_get(dev, NULL);
> -	} else {
> -		gpu->icc_path = of_icc_get(dev, "gfx-mem");
> -		gpu->ocmem_icc_path = of_icc_get(dev, "ocmem");
> -	}
>  
> -	if (IS_ERR(gpu->icc_path)) {
> -		ret = PTR_ERR(gpu->icc_path);
> -		gpu->icc_path = NULL;
> -		return ret;
> -	}
> -
> -	if (IS_ERR(gpu->ocmem_icc_path)) {
> -		ret = PTR_ERR(gpu->ocmem_icc_path);
> -		gpu->ocmem_icc_path = NULL;
> -		/* allow -ENODATA, ocmem icc is optional */
> -		if (ret != -ENODATA)
> -			return ret;
> -	}
> -
> -	return 0;
> +	return ret;

This could go even further:

return msm_gpu_init(...);

>  }
>  
>  void adreno_gpu_cleanup(struct adreno_gpu *adreno_gpu)
> -- 
> 2.7.4
> 

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