linux-kernel - Re: [PATCH 4/4] drivers: qcom: rpmh-rsc: Add RSC power domain support

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Date:   Wed, 14 Aug 2019 11:25:01 -0700
From:   Stephen Boyd <swboyd@...omium.org>
To:     Maulik Shah <mkshah@...eaurora.org>, agross@...nel.org,
        david.brown@...aro.org, linux-arm-msm@...r.kernel.org
Cc:     linux-kernel@...r.kernel.org, linux-pm@...r.kernel.org,
        bjorn.andersson@...aro.org, evgreen@...omium.org,
        dianders@...omium.org, rnayak@...eaurora.org, ilina@...eaurora.org,
        lsrao@...eaurora.org, ulf.hansson@...aro.org,
        Maulik Shah <mkshah@...eaurora.org>
Subject: Re: [PATCH 4/4] drivers: qcom: rpmh-rsc: Add RSC power domain support

Quoting Maulik Shah (2019-08-13 01:24:42)
> diff --git a/drivers/soc/qcom/rpmh-rsc.c b/drivers/soc/qcom/rpmh-rsc.c
> index e278fc11fe5c..bd8e9f1a43b4 100644
> --- a/drivers/soc/qcom/rpmh-rsc.c
> +++ b/drivers/soc/qcom/rpmh-rsc.c
> @@ -498,6 +498,32 @@ static int tcs_ctrl_write(struct rsc_drv *drv, const struct tcs_request *msg)
>         return ret;
>  }
>  
> +/**
> + *  rpmh_rsc_ctrlr_is_idle: Check if any of the AMCs are busy.
> + *
> + *  @drv: The controller
> + *
> + *  Returns false if the TCSes are engaged in handling requests,
> + *  True if controller is idle.
> + */
> +static bool rpmh_rsc_ctrlr_is_idle(struct rsc_drv *drv)
> +{
> +       int m;
> +       struct tcs_group *tcs = get_tcs_of_type(drv, ACTIVE_TCS);
> +       bool ret = true;
> +
> +       spin_lock(&drv->lock);
> +       for (m = tcs->offset; m < tcs->offset + tcs->num_tcs; m++) {
> +               if (!tcs_is_free(drv, m)) {

Isn't this a copy of an existing function in the rpmh driver?

> +                       ret = false;
> +                       break;
> +               }
> +       }
> +       spin_unlock(&drv->lock);
> +
> +       return ret;
> +}
> +
>  /**
>   * rpmh_rsc_write_ctrl_data: Write request to the controller
>   *
> @@ -521,6 +547,65 @@ int rpmh_rsc_write_ctrl_data(struct rsc_drv *drv, const struct tcs_request *msg)
>         return tcs_ctrl_write(drv, msg);
>  }
>  
> +int rpmh_domain_power_off(struct generic_pm_domain *rsc_pd)
> +{
> +       struct rsc_drv *drv = container_of(rsc_pd, struct rsc_drv, rsc_pd);
> +       int ret = 0;
> +
> +       /*
> +        * RPMh domain can not be powered off when there is pending ACK for
> +        * ACTIVE_TCS request. Exit when controller is busy.
> +        */
> +
> +       ret = rpmh_rsc_ctrlr_is_idle(drv);
> +       if (!ret)
> +               goto exit;

return 0? Shouldn't it return some negative value?

> +
> +       ret = rpmh_flush(&drv->client);
> +       if (ret)
> +               goto exit;

Why not just return rpmh_flush(...)?

The usage of goto in this function is entirely unnecessary.

> +
> +exit:
> +       return ret;
> +}
> +
> +static int rpmh_probe_power_domain(struct platform_device *pdev,
> +                                  struct rsc_drv *drv)
> +{
> +       int ret = -ENOMEM;
> +       struct generic_pm_domain *rsc_pd = &drv->rsc_pd;
> +       struct device_node *dn = pdev->dev.of_node;
> +
> +       rsc_pd->name = kasprintf(GFP_KERNEL, "%s", dn->name);
> +       if (!rsc_pd->name)
> +               goto exit;

return -ENOMEM;

> +
> +       rsc_pd->name = kbasename(rsc_pd->name);
> +       rsc_pd->power_off = rpmh_domain_power_off;
> +       rsc_pd->flags |= GENPD_FLAG_IRQ_SAFE;
> +
> +       ret = pm_genpd_init(rsc_pd, NULL, false);
> +       if (ret)
> +               goto free_name;
> +
> +       ret = of_genpd_add_provider_simple(dn, rsc_pd);
> +       if (ret)
> +               goto remove_pd;
> +
> +       pr_debug("init PM domain %s\n", rsc_pd->name);
> +
> +       return ret;

	ret = of_genpd_add_provider_simple(...)
	if (!ret)
		return 0;

Drop the pr_debug(), it's not useful.

> +
> +remove_pd:
> +       pm_genpd_remove(rsc_pd);
> +
> +free_name:
> +       kfree(rsc_pd->name);
> +
> +exit:
> +       return ret;

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