Re: [PATCH 2/2] drm/panfrost: add devfreq regulator support

[ClÃment PÃron]

Hi Panfrost and OPP Maintainers,

On Sat, 11 Apr 2020 at 22:06, ClÃment PÃron <peron.clem@xxxxxxxxx> wrote:
>
> OPP table can defined both frequency and voltage.
>
> Register the mali regulator if it exist.

After this patch, Panfrost update properly both voltage and frequency.
But the GPU is still not properly down-clocked when temperature is high.

I try to add a cooling map like this :
https://github.com/clementperon/linux/commit/955961c7c035abbf44e74f608fe8f059c06a2fbe

But got the following error:
[    2.712082] panfrost 1800000.gpu: [drm:panfrost_devfreq_init
[panfrost]] Failed to register cooling device

Do you see what I'm missing?

Thanks for your help,
Clement



>
> Signed-off-by: ClÃment PÃron <peron.clem@xxxxxxxxx>
> ---
>  drivers/gpu/drm/panfrost/panfrost_devfreq.c | 34 ++++++++++++++++++---
>  drivers/gpu/drm/panfrost/panfrost_device.h  |  1 +
>  2 files changed, 31 insertions(+), 4 deletions(-)
>
> diff --git a/drivers/gpu/drm/panfrost/panfrost_devfreq.c b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> index 62541f4edd81..2dc8e2355358 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> +++ b/drivers/gpu/drm/panfrost/panfrost_devfreq.c
> @@ -78,12 +78,26 @@ int panfrost_devfreq_init(struct panfrost_device *pfdev)
>         struct device *dev = &pfdev->pdev->dev;
>         struct devfreq *devfreq;
>         struct thermal_cooling_device *cooling;
> +       const char *mali = "mali";
> +       struct opp_table *opp_table = NULL;
> +
> +       /* Regulator is optional */
> +       opp_table = dev_pm_opp_set_regulators(dev, &mali, 1);
> +       if (IS_ERR(opp_table)) {
> +               ret = PTR_ERR(opp_table);
> +               if (ret != -ENODEV) {
> +                       DRM_DEV_ERROR(dev, "Failed to set regulator: %d\n", ret);
> +                       return ret;
> +               }
> +       }
> +       pfdev->devfreq.opp_table = opp_table;
>
>         ret = dev_pm_opp_of_add_table(dev);
> -       if (ret == -ENODEV) /* Optional, continue without devfreq */
> -               return 0;
> -       else if (ret)
> -               return ret;
> +       if (ret) {
> +               if (ret == -ENODEV) /* Optional, continue without devfreq */
> +                       ret = 0;
> +               goto err_opp_reg;
> +       }
>
>         panfrost_devfreq_reset(pfdev);
>
> @@ -119,6 +133,12 @@ int panfrost_devfreq_init(struct panfrost_device *pfdev)
>  err_opp:
>         dev_pm_opp_of_remove_table(dev);
>
> +err_opp_reg:
> +       if (pfdev->devfreq.opp_table) {
> +               dev_pm_opp_put_regulators(pfdev->devfreq.opp_table);
> +               pfdev->devfreq.opp_table = NULL;
> +       }
> +
>         return ret;
>  }
>
> @@ -126,7 +146,13 @@ void panfrost_devfreq_fini(struct panfrost_device *pfdev)
>  {
>         if (pfdev->devfreq.cooling)
>                 devfreq_cooling_unregister(pfdev->devfreq.cooling);
> +
>         dev_pm_opp_of_remove_table(&pfdev->pdev->dev);
> +
> +       if (pfdev->devfreq.opp_table) {
> +               dev_pm_opp_put_regulators(pfdev->devfreq.opp_table);
> +               pfdev->devfreq.opp_table = NULL;
> +       }
>  }
>
>  void panfrost_devfreq_resume(struct panfrost_device *pfdev)
> diff --git a/drivers/gpu/drm/panfrost/panfrost_device.h b/drivers/gpu/drm/panfrost/panfrost_device.h
> index 06713811b92c..f6b0c779dfe5 100644
> --- a/drivers/gpu/drm/panfrost/panfrost_device.h
> +++ b/drivers/gpu/drm/panfrost/panfrost_device.h
> @@ -86,6 +86,7 @@ struct panfrost_device {
>         struct {
>                 struct devfreq *devfreq;
>                 struct thermal_cooling_device *cooling;
> +               struct opp_table *opp_table;
>                 ktime_t busy_time;
>                 ktime_t idle_time;
>                 ktime_t time_last_update;
> --
> 2.20.1
>