From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eduardo Valentin Subject: Re: [PATCH v2 1/2] thermal: add available policies attribut Date: Wed, 15 Jan 2014 10:00:55 -0400 Message-ID: <52D69497.1030903@ti.com> References: <1389611863-7812-1-git-send-email-wni@nvidia.com> <1389611863-7812-2-git-send-email-wni@nvidia.com> <52D40D36.9060702@ti.com> <52D67066.8010403@nvidia.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="Emwgp4cxH6x8tGd0WmMV3FADlGWa7WOal" Return-path: In-Reply-To: <52D67066.8010403-DDmLM1+adcrQT0dZR+AlfA@public.gmane.org> Sender: linux-tegra-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Wei Ni Cc: Eduardo Valentin , "rui.zhang-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org" , "mark.rutland-5wv7dgnIgG8@public.gmane.org" , "durgadoss.r-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org" , Matthew Longnecker , "swarren-3lzwWm7+Weoh9ZMKESR00Q@public.gmane.org" , "linux-pm-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" , "linux-tegra-u79uwXL29TY76Z2rM5mHXA@public.gmane.org" List-Id: linux-tegra@vger.kernel.org --Emwgp4cxH6x8tGd0WmMV3FADlGWa7WOal Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: quoted-printable On 15-01-2014 07:26, Wei Ni wrote: > On 01/13/2014 11:58 PM, Eduardo Valentin wrote: >> * PGP Signed by an unknown key >> >> On 13-01-2014 07:17, Wei Ni wrote: >>> The Linux thermal framework support to change governor policy >>> in run time, but it can't show what available policies supported. >>> >>> This patch adds available_policies attribut to the thermal >> >> s/attribut/attribute/g >=20 > oh, thanks, I will fix it. >=20 >> >>> framework, it can list the thermal governors which can be >>> used for a particular zone. This attribut is read only. >>> >>> Signed-off-by: Wei Ni >>> --- >>> Documentation/thermal/sysfs-api.txt | 6 ++++++ >>> drivers/thermal/thermal_core.c | 25 +++++++++++++++++++++++++= >>> 2 files changed, 31 insertions(+) >>> >>> diff --git a/Documentation/thermal/sysfs-api.txt b/Documentation/ther= mal/sysfs-api.txt >>> index 87519cb..6a70b55c 100644 >>> --- a/Documentation/thermal/sysfs-api.txt >>> +++ b/Documentation/thermal/sysfs-api.txt >>> @@ -172,6 +172,7 @@ Thermal zone device sys I/F, created once it's re= gistered: >>> |---temp: Current temperature >>> |---mode: Working mode of the thermal zone >>> |---policy: Thermal governor used for this zone >>> + |---available_policies Available governors for this zone >> >> I would prefer: >> "Available thermal governors for this zone" >=20 > Ok. >=20 >> >>> |---trip_point_[0-*]_temp: Trip point temperature >>> |---trip_point_[0-*]_type: Trip point type >>> |---trip_point_[0-*]_hyst: Hysteresis value for this trip point >>> @@ -238,6 +239,10 @@ policy >>> One of the various thermal governors used for a particular zone. >>> RW, Required >>> =20 >>> +available_policies >>> + Availabe thermal governors which can be used for a particular zone.= >>> + RO, Required >>> + >>> trip_point_[0-*]_temp >>> The temperature above which trip point will be fired. >>> Unit: millidegree Celsius >>> @@ -330,6 +335,7 @@ method, the sys I/F structure will be built like = this: >>> |---temp: 37000 >>> |---mode: enabled >>> |---policy: step_wise >>> + |---available_policies: step_wise fair_share >>> |---trip_point_0_temp: 100000 >>> |---trip_point_0_type: critical >>> |---trip_point_1_temp: 80000 >>> diff --git a/drivers/thermal/thermal_core.c b/drivers/thermal/thermal= _core.c >>> index 338a88b..aab1df8 100644 >>> --- a/drivers/thermal/thermal_core.c >>> +++ b/drivers/thermal/thermal_core.c >>> @@ -761,6 +761,24 @@ policy_show(struct device *dev, struct device_at= tribute *devattr, char *buf) >>> return sprintf(buf, "%s\n", tz->governor->name); >>> } >>> =20 >>> +static ssize_t >>> +available_policies_show(struct device *dev, struct device_attribute = *devattr, >>> + char *buf) >>> +{ >>> + struct thermal_governor *pos; >>> + ssize_t count =3D 0; >>> + >>> + mutex_lock(&thermal_governor_lock); >>> + >>> + list_for_each_entry(pos, &thermal_governor_list, governor_list) >>> + count +=3D sprintf(buf + count, "%s ", pos->name); >> >> I would prefer if you'd used scnprintf >> >>> + count +=3D sprintf(buf + count, "\n"); >> >> ditto. >> >> >> It is unlikely, but What if count if greater than PAGE_SIZE? >=20 > hmm, I checked the sysfs driver, in funciton sysfs_kf_seq_show(), it > seems it can handle the count greater than PAGE_SIZE. > Or we can return error here directly. > What do you think about it? Just to be aware that it will truncate your buffer: /* * The code works fine with PAGE_SIZE return but it's likely to * indicate truncated result or overflow in normal use cases. */ if (count >=3D (ssize_t)PAGE_SIZE) { print_symbol("fill_read_buffer: %s returned bad count\n", (unsigned long)ops->show); /* Try to struggle along */ count =3D PAGE_SIZE - 1; } So, you either truncate here or leave to sysfs_seq_show(). Leave at least a comment in case you leave to sysfs layer. >=20 >> >>> + >>> + mutex_unlock(&thermal_governor_lock); >>> + >>> + return count; >>> +} >>> + >>> #ifdef CONFIG_THERMAL_EMULATION >>> static ssize_t >>> emul_temp_store(struct device *dev, struct device_attribute *attr, >>> @@ -794,6 +812,7 @@ static DEVICE_ATTR(temp, 0444, temp_show, NULL); >>> static DEVICE_ATTR(mode, 0644, mode_show, mode_store); >>> static DEVICE_ATTR(passive, S_IRUGO | S_IWUSR, passive_show, passive= _store); >>> static DEVICE_ATTR(policy, S_IRUGO | S_IWUSR, policy_show, policy_st= ore); >>> +static DEVICE_ATTR(available_policies, S_IRUGO, available_policies_s= how, NULL); >>> =20 >>> /* sys I/F for cooling device */ >>> #define to_cooling_device(_dev) \ >>> @@ -1527,6 +1546,11 @@ struct thermal_zone_device *thermal_zone_devic= e_register(const char *type, >>> if (result) >>> goto unregister; >>> =20 >>> + /* Create available_policies attribute */ >>> + result =3D device_create_file(&tz->device, &dev_attr_available_poli= cies); >>> + if (result) >>> + goto unregister; >>> + >>> /* Update 'this' zone's governor information */ >>> mutex_lock(&thermal_governor_lock); >>> =20 >>> @@ -1622,6 +1646,7 @@ void thermal_zone_device_unregister(struct ther= mal_zone_device *tz) >>> if (tz->ops->get_mode) >>> device_remove_file(&tz->device, &dev_attr_mode); >>> device_remove_file(&tz->device, &dev_attr_policy); >>> + device_remove_file(&tz->device, &dev_attr_available_policies); >>> remove_trip_attrs(tz); >>> tz->governor =3D NULL; >>> =20 >>> >> >> >=20 >=20 >=20 --=20 You have got to be excited about what you are doing. (L. Lamport) Eduardo Valentin --Emwgp4cxH6x8tGd0WmMV3FADlGWa7WOal Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.12 (GNU/Linux) Comment: Using GnuPG with Thunderbird - http://www.enigmail.net/ iF4EAREIAAYFAlLWlJcACgkQCXcVR3XQvP27EAEA/BtrYIJeTh6od2NAZ4nMgT8G qIat+4mDXACiGgGzUPkBAICVxhuBhLMLny3XF3nW6Au97zFvrIyjt/5Xa0DtVi9R =rirf -----END PGP SIGNATURE----- --Emwgp4cxH6x8tGd0WmMV3FADlGWa7WOal--