LKML Archive on lore.kernel.org
 help / color / Atom feed
From: Matthias Kaehlcke <mka@chromium.org>
To: Wei Wang <wvw@google.com>
Cc: wei.vince.wang@gmail.com, Zhang Rui <rui.zhang@intel.com>,
	Eduardo Valentin <edubezval@gmail.com>,
	Daniel Lezcano <daniel.lezcano@linaro.org>,
	Amit Kucheria <amit.kucheria@verdurent.com>,
	linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
	Amit Kucheria <amit.kucheria@linaro.org>
Subject: Re: [PATCH v3 3/3] thermal: create softlink by name for thermal_zone and cooling_device
Date: Fri, 6 Dec 2019 11:15:45 -0800
Message-ID: <20191206191545.GO228856@google.com> (raw)
In-Reply-To: <20191205071953.121511-4-wvw@google.com>

On Wed, Dec 04, 2019 at 11:19:53PM -0800, Wei Wang wrote:
> The paths thermal_zone%d and cooling_device%d are not intuitive and the
> numbers are subject to change due to device tree change. This usually
> leads to tree traversal in userspace code.
> The patch creates `tz-by-name' and `cdev-by-name' for thermal zone and
> cooling_device respectively.

This is useful, especially for systems with plenty of thermal zones :)

> Signed-off-by: Wei Wang <wvw@google.com>
> Reviewed-by: Amit Kucheria <amit.kucheria@linaro.org>
> ---
>  drivers/thermal/thermal_core.c | 21 ++++++++++++++++++++-
>  1 file changed, 20 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal_core.c
> index 9db7f72e70f8..7872bd527f3f 100644
> --- a/drivers/thermal/thermal_core.c
> +++ b/drivers/thermal/thermal_core.c
> @@ -22,6 +22,7 @@
>  #include <net/netlink.h>
>  #include <net/genetlink.h>
>  #include <linux/suspend.h>
> +#include <linux/kobject.h>
>  
>  #define CREATE_TRACE_POINTS
>  #include <trace/events/thermal.h>
> @@ -46,6 +47,8 @@ static DEFINE_MUTEX(poweroff_lock);
>  
>  static atomic_t in_suspend;
>  static bool power_off_triggered;
> +static struct kobject *cdev_link_kobj;
> +static struct kobject *tz_link_kobj;
>  
>  static struct thermal_governor *def_governor;
>  
> @@ -999,9 +1002,15 @@ __thermal_cooling_device_register(struct device_node *np,
>  		return ERR_PTR(result);
>  	}
>  
> -	/* Add 'this' new cdev to the global cdev list */
> +	/* Add 'this' new cdev to the global cdev list and create link*/
>  	mutex_lock(&thermal_list_lock);
>  	list_add(&cdev->node, &thermal_cdev_list);
> +	if (!cdev_link_kobj)
> +		cdev_link_kobj = kobject_create_and_add("cdev-by-name",
> +						cdev->device.kobj.parent);
> +	if (!cdev_link_kobj || sysfs_create_link(cdev_link_kobj,
> +						&cdev->device.kobj, cdev->type))
> +		dev_err(&cdev->device, "Failed to create cdev-by-name link\n");
>  	mutex_unlock(&thermal_list_lock);
>  
>  	/* Update binding information for 'this' new cdev */
> @@ -1167,6 +1176,8 @@ void thermal_cooling_device_unregister(struct thermal_cooling_device *cdev)
>  			}
>  		}
>  	}
> +	if (cdev_link_kobj)
> +		sysfs_remove_link(cdev_link_kobj, cdev->type);
>  
>  	mutex_unlock(&thermal_list_lock);
>  
> @@ -1354,6 +1365,12 @@ thermal_zone_device_register(const char *type, int trips, int mask,
>  
>  	mutex_lock(&thermal_list_lock);
>  	list_add_tail(&tz->node, &thermal_tz_list);
> +	if (!tz_link_kobj)
> +		tz_link_kobj = kobject_create_and_add("tz-by-name",
> +						tz->device.kobj.parent);
> +	if (!tz_link_kobj || sysfs_create_link(tz_link_kobj,
> +						&tz->device.kobj, tz->type))
> +		dev_err(&tz->device, "Failed to create tz-by-name link\n");
>  	mutex_unlock(&thermal_list_lock);
>  
>  	/* Bind cooling devices for this zone */
> @@ -1425,6 +1442,8 @@ void thermal_zone_device_unregister(struct thermal_zone_device *tz)
>  			}
>  		}
>  	}
> +	if (tz_link_kobj)
> +		sysfs_remove_link(tz_link_kobj, tz->type);
>  
>  	mutex_unlock(&thermal_list_lock);
>  

Reviewed-by: Matthias Kaehlcke <mka@chromium.org>
Tested-by: Matthias Kaehlcke <mka@chromium.org>


  reply index

Thread overview: 22+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2019-12-05  7:19 [PATCH v3 0/3] thermal: introduce by-name softlink Wei Wang
2019-12-05  7:19 ` [PATCH v3 1/3] thermal: prevent cooling device with no type to be registered Wei Wang
2019-12-09  7:41   ` Amit Kucheria
2019-12-09 17:34     ` Wei Wang
2019-12-09 19:36   ` Daniel Lezcano
2019-12-09 21:13     ` Wei Wang
2019-12-05  7:19 ` [PATCH v3 2/3] thermal: improve error message in thermal zone registration Wei Wang
2019-12-09  7:41   ` Amit Kucheria
2019-12-05  7:19 ` [PATCH v3 3/3] thermal: create softlink by name for thermal_zone and cooling_device Wei Wang
2019-12-06 19:15   ` Matthias Kaehlcke [this message]
2019-12-09  7:42   ` Amit Kucheria
2019-12-10 14:36 ` [PATCH v3 0/3] thermal: introduce by-name softlink Daniel Lezcano
2019-12-10 20:01   ` Wei Wang
2019-12-10 20:54     ` Daniel Lezcano
2019-12-11  8:53       ` Greg Kroah-Hartman
2019-12-11  8:54       ` Greg Kroah-Hartman
2019-12-11 20:11         ` Wei Wang
2019-12-11 21:11           ` Daniel Lezcano
2019-12-11 22:19             ` Wei Wang
2019-12-15 16:34               ` Sandeep Patil
2019-12-16 17:37                 ` Wei Wang
2019-12-12  7:34           ` Greg Kroah-Hartman

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=20191206191545.GO228856@google.com \
    --to=mka@chromium.org \
    --cc=amit.kucheria@linaro.org \
    --cc=amit.kucheria@verdurent.com \
    --cc=daniel.lezcano@linaro.org \
    --cc=edubezval@gmail.com \
    --cc=linux-kernel@vger.kernel.org \
    --cc=linux-pm@vger.kernel.org \
    --cc=rui.zhang@intel.com \
    --cc=wei.vince.wang@gmail.com \
    --cc=wvw@google.com \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link

LKML Archive on lore.kernel.org

Archives are clonable:
	git clone --mirror https://lore.kernel.org/lkml/0 lkml/git/0.git
	git clone --mirror https://lore.kernel.org/lkml/1 lkml/git/1.git
	git clone --mirror https://lore.kernel.org/lkml/2 lkml/git/2.git
	git clone --mirror https://lore.kernel.org/lkml/3 lkml/git/3.git
	git clone --mirror https://lore.kernel.org/lkml/4 lkml/git/4.git
	git clone --mirror https://lore.kernel.org/lkml/5 lkml/git/5.git
	git clone --mirror https://lore.kernel.org/lkml/6 lkml/git/6.git
	git clone --mirror https://lore.kernel.org/lkml/7 lkml/git/7.git
	git clone --mirror https://lore.kernel.org/lkml/8 lkml/git/8.git
	git clone --mirror https://lore.kernel.org/lkml/9 lkml/git/9.git

	# If you have public-inbox 1.1+ installed, you may
	# initialize and index your mirror using the following commands:
	public-inbox-init -V2 lkml lkml/ https://lore.kernel.org/lkml \
		linux-kernel@vger.kernel.org
	public-inbox-index lkml

Example config snippet for mirrors

Newsgroup available over NNTP:
	nntp://nntp.lore.kernel.org/org.kernel.vger.linux-kernel


AGPL code for this site: git clone https://public-inbox.org/public-inbox.git