Re: [PATCH v4 3/7] drm/panfrost: Improve error reporting in panfrost_gpu_power_on

[Matthias Brugger <matthias.bgg@gmail.com>]

On 07/02/2020 06:26, Nicolas Boichat wrote:
> It is useful to know which component cannot be powered on.
> 
> Signed-off-by: Nicolas Boichat <drinkcat@chromium.org>
> Reviewed-by: Steven Price <steven.price@arm.com>
> Reviewed-by: Alyssa Rosenzweig <alyssa.rosenzweig@collabora.com>

Reviewed-by: Matthias Brugger <mbrugger@suse.com>

> ---
> 
> Was useful when trying to probe Bifrost GPU, to understand what
> issue we are facing.
> 
> v4:
>  - No change
> v3:
>  - Rebased on https://patchwork.kernel.org/patch/11325689/
> 
>  drivers/gpu/drm/panfrost/panfrost_gpu.c | 11 +++++++----
>  1 file changed, 7 insertions(+), 4 deletions(-)
> 
> diff --git a/drivers/gpu/drm/panfrost/panfrost_gpu.c b/drivers/gpu/drm/panfrost/panfrost_gpu.c
> index 460fc190de6e815..856f2fd1fa8ed27 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_gpu.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_gpu.c
> @@ -308,17 +308,20 @@ void panfrost_gpu_power_on(struct panfrost_device *pfdev)
>  	gpu_write(pfdev, L2_PWRON_LO, pfdev->features.l2_present);
>  	ret = readl_relaxed_poll_timeout(pfdev->iomem + L2_READY_LO,
>  		val, val == pfdev->features.l2_present, 100, 1000);
> +	if (ret)
> +		dev_err(pfdev->dev, "error powering up gpu L2");
>  
>  	gpu_write(pfdev, SHADER_PWRON_LO, pfdev->features.shader_present);
> -	ret |= readl_relaxed_poll_timeout(pfdev->iomem + SHADER_READY_LO,
> +	ret = readl_relaxed_poll_timeout(pfdev->iomem + SHADER_READY_LO,
>  		val, val == pfdev->features.shader_present, 100, 1000);
> +	if (ret)
> +		dev_err(pfdev->dev, "error powering up gpu shader");
>  
>  	gpu_write(pfdev, TILER_PWRON_LO, pfdev->features.tiler_present);
> -	ret |= readl_relaxed_poll_timeout(pfdev->iomem + TILER_READY_LO,
> +	ret = readl_relaxed_poll_timeout(pfdev->iomem + TILER_READY_LO,
>  		val, val == pfdev->features.tiler_present, 100, 1000);
> -
>  	if (ret)
> -		dev_err(pfdev->dev, "error powering up gpu");
> +		dev_err(pfdev->dev, "error powering up gpu tiler");
>  }
>  
>  void panfrost_gpu_power_off(struct panfrost_device *pfdev)
>