Re: [Patch v5 3/6] thermal: Add generic power domain warming device driver.

[Thara Gopinath]

Hi Ulf,
Thanks for the review!

On 3/23/20 11:57 AM, Ulf Hansson wrote:

--snip
> > +
> > +static void pd_warming_release(struct device *dev)
> > +{
> > +       kfree(dev);
>
> This is wrong, you should free a "struct pd_warming_device *". Use the
> "container of" macro to get it from 'dev'.

Will fix this.
> > +}
> > +
> > +struct thermal_cooling_device *
> > +of_pd_warming_register(struct device *parent, int pd_id)
> > +{
> > +       struct pd_warming_device *pd_wdev;
> > +       struct of_phandle_args pd_args;
> > +       char cdev_name[THERMAL_NAME_LENGTH];
> > +       int ret;
> > +
> > +       pd_wdev = kzalloc(sizeof(*pd_wdev), GFP_KERNEL);
> > +       if (!pd_wdev)
> > +               return ERR_PTR(-ENOMEM);
> > +
> > +       dev_set_name(&pd_wdev->dev, "%s_%d_warming_dev",
> > +                    dev_name(parent), pd_id);
> > +       pd_wdev->dev.parent = parent;
> > +       pd_wdev->dev.release = pd_warming_release;
> > +
> > +       ret = device_register(&pd_wdev->dev);
> > +       if (ret) {
> > +               put_device(&pd_wdev->dev);
> > +               goto free_pd_wdev;
> > +       }
> > +
> > +       ret = ida_simple_get(&pd_ida, 0, 0, GFP_KERNEL);
> > +       if (ret < 0)
> > +               goto unregister_device;
>
> If you use and ida, you might as well use it as a part of the
> dev_set_name() above.
>
> That should give you a unique name, similar to how you use it for the
> cdev_name below.

dev_set_name above already has a unique name with the power controller 
name and the power domain id. cdev on the other hand creates a virtual 
thermal device and needs a unique name.

> > +
> > +       pd_wdev->id = ret;
> > +
> > +       pd_args.np = parent->of_node;
> > +       pd_args.args[0] = pd_id;
> > +       pd_args.args_count = 1;
> > +
> > +       ret = of_genpd_add_device(&pd_args, &pd_wdev->dev);
> > +
> > +       if (ret)
> > +               goto remove_ida;
> > +
> > +       ret = dev_pm_genpd_performance_state_count(&pd_wdev->dev);
> > +       if (ret < 0)
> > +               goto out_genpd;
> > +
> > +       pd_wdev->max_state = ret - 1;
> > +       pm_runtime_enable(&pd_wdev->dev);
> > +       pd_wdev->runtime_resumed = false;
> > +
> > +       snprintf(cdev_name, sizeof(cdev_name), "thermal-pd-%d", pd_wdev->id);
> > +       pd_wdev->cdev = thermal_of_cooling_device_register
> > +                                       (NULL, cdev_name, pd_wdev,
> > +                                        &pd_warming_device_ops);
> > +       if (IS_ERR(pd_wdev->cdev)) {
> > +               pr_err("unable to register %s cooling device\n", cdev_name);
> > +               ret = PTR_ERR(pd_wdev->cdev);
> > +               goto out_runtime_disable;
> > +       }
> > +
> > +       return pd_wdev->cdev;
> > +
> > +out_runtime_disable:
> > +       pm_runtime_disable(&pd_wdev->dev);
> > +out_genpd:
> > +       pm_genpd_remove_device(&pd_wdev->dev);
> > +remove_ida:
> > +       ida_simple_remove(&pd_ida, pd_wdev->id);
> > +unregister_device:
> > +       device_unregister(&pd_wdev->dev);
> > +       pd_warming_release(&pd_wdev->dev);
>
> This is wrong, drop this.

Oops . sorry . Will do. Will fix rest of the comments below as well.

> > +free_pd_wdev:
> > +       kfree(pd_wdev);
>
> Since you should free this from the ->release() callback, there is no
> need to do this here.
>
> > +       return ERR_PTR(ret);
> > +}
> > +EXPORT_SYMBOL_GPL(of_pd_warming_register);
> > +
> > +void pd_warming_unregister(struct thermal_cooling_device *cdev)
> > +{
> > +       struct pd_warming_device *pd_wdev = cdev->devdata;
> > +       struct device *dev = &pd_wdev->dev;
> > +
> > +       if (pd_wdev->runtime_resumed) {
> > +               dev_pm_genpd_set_performance_state(dev, 0);
> > +               pm_runtime_put(dev);
> > +               pd_wdev->runtime_resumed = false;
> > +       }
> > +       pm_runtime_disable(dev);
> > +       pm_genpd_remove_device(dev);
> > +       ida_simple_remove(&pd_ida, pd_wdev->id);
> > +       thermal_cooling_device_unregister(cdev);
> > +       kfree(pd_wdev);
>
> Don't use kfree here, but instead device_unregister(dev);
>
> > +}
> > +EXPORT_SYMBOL_GPL(pd_warming_unregister);
> > diff --git a/include/linux/pd_warming.h b/include/linux/pd_warming.h
> > new file mode 100644
> > index 000000000000..550a5683b56d
> > --- /dev/null
> > +++ b/include/linux/pd_warming.h
> > @@ -0,0 +1,29 @@
> > +// SPDX-License-Identifier: GPL-2.0
> > +/*
> > + * Copyright (c) 2019, Linaro Ltd.
> > + */
> > +#ifndef __PWR_DOMAIN_WARMING_H__
> > +#define __PWR_DOMAIN_WARMING_H__
> > +
> > +#include <linux/pm_domain.h>
> > +#include <linux/thermal.h>
> > +
> > +#ifdef CONFIG_PWR_DOMAIN_WARMING_THERMAL
> > +struct thermal_cooling_device *
> > +of_pd_warming_register(struct device *parent, int pd_id);
> > +
> > +void pd_warming_unregister(struct thermal_cooling_device *cdev);
> > +
> > +#else
> > +static inline struct thermal_cooling_device *
> > +of_pd_warming_register(struct device *parent, int pd_id)
> > +{
> > +       return ERR_PTR(-ENOSYS);
> > +}
> > +
> > +static inline void
> > +pd_warming_unregister(struct thermal_cooling_device *cdev)
> > +{
> > +}
> > +#endif /* CONFIG_PWR_DOMAIN_WARMING_THERMAL */
> > +#endif /* __PWR_DOMAIN_WARMING_H__ */
> > --
> > 2.20.1
>
> Besides the few things above, this looks good to me.
>
> Kind regards
> Uffe

--
Warm Regards
Thara