Re: [PATCH v2 4/6] drivers: qcom: rpmh-rsc: Add RSC power domain support

[Maulik Shah]

On 9/5/2019 11:02 PM, Stephen Boyd wrote:
> Quoting Maulik Shah (2019-08-23 01:17:01)
> > diff --git a/drivers/soc/qcom/rpmh-rsc.c b/drivers/soc/qcom/rpmh-rsc.c
> > index e278fc11fe5c..884b39599e8f 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,
> Please use kernel-doc style for returns here.
Done.
> > + *  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);
> I think these need to be irqsave/restore still.
Done.
> > +       for (m = tcs->offset; m < tcs->offset + tcs->num_tcs; m++) {
> > +               if (!tcs_is_free(drv, m)) {
> This snippet is from tcs_invalidate(). Please collapse it into some sort
> of function or macro like for_each_tcs().
Keeping it as it is, the snippet is actually little different from 
tcs_invalidate.
> > +                       ret = false;
> > +                       break;
> > +               }
> > +       }
> > +       spin_unlock(&drv->lock);
> > +
> > +       return ret;
> > +}
> > +
> >   /**
> >    * rpmh_rsc_write_ctrl_data: Write request to the controller
> >    *
> > @@ -521,6 +547,53 @@ int rpmh_rsc_write_ctrl_data(struct rsc_drv *drv, const struct tcs_request *msg)
> >          return tcs_ctrl_write(drv, msg);
> >   }
> >   
> > +static int rpmh_domain_power_off(struct generic_pm_domain *rsc_pd)
> > +{
> > +       struct rsc_drv *drv = container_of(rsc_pd, struct rsc_drv, rsc_pd);
> > +
> > +       /*
> > +        * RPMh domain can not be powered off when there is pending ACK for
> > +        * ACTIVE_TCS request. Exit when controller is busy.
> > +        */
> > +
> Nitpick: Remove this extra newline.
Done.
> > +       if (!rpmh_rsc_ctrlr_is_idle(drv))
> > +               return -EBUSY;
> > +
> > +       return rpmh_flush(&drv->client);
> > +}
> > +
> > +static int rpmh_probe_power_domain(struct platform_device *pdev,
> > +                                  struct rsc_drv *drv)
> > +{
> > +       int ret;
> > +       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);
> Maybe use devm_kasprintf?
Done.
> > +       if (!rsc_pd->name)
> > +               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;
> > +
> > +       return ret;
> > +
> > +remove_pd:
> > +       pm_genpd_remove(rsc_pd);
> > +free_name:
> > +       kfree(rsc_pd->name);
> And then drop this one?
Done.
> > +       return ret;
> > +}
> > +
> >   static int rpmh_probe_tcs_config(struct platform_device *pdev,
> >                                   struct rsc_drv *drv)
> >   {
> > @@ -650,6 +723,17 @@ static int rpmh_rsc_probe(struct platform_device *pdev)
> >          if (ret)
> >                  return ret;
> >   
> > +       /*
> > +        * Power domain is not required for controllers that support 'solver'
> > +        * mode where they can be in autonomous mode executing low power mode
> > +        * to power down.
> > +        */
> > +       if (of_property_read_bool(dn, "#power-domain-cells")) {
> > +               ret = rpmh_probe_power_domain(pdev, drv);
> > +               if (ret)
> > +                       return ret;
> > +       }
> > +
> >          spin_lock_init(&drv->lock);
> >          bitmap_zero(drv->tcs_in_use, MAX_TCS_NR);
> What happens if it fails later on? The genpd provider is still sitting
> around and needs to be removed on probe failure later on in this
> function. It would be nicer if there wasn't another function to probe
> the power domain and it was just inlined here actually. That way we
> don't have to wonder about what's going on across two blocks of code.

Thanks for pointing this. Moved it at the end of probe to avoid this.

>
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