From: Eduardo Valentin <edubezval@gmail.com>
To: "Rafael J. Wysocki" <rafael@kernel.org>
Cc: Rui Zhang <rui.zhang@intel.com>,
"Rafael J. Wysocki" <rjw@rjwysocki.net>,
Len Brown <lenb@kernel.org>,
ACPI Devel Maling List <linux-acpi@vger.kernel.org>,
"Lee, Chun-Yi" <jlee@suse.com>,
Darren Hart <dvhart@infradead.org>, Keerthy <j-keerthy@ti.com>,
Linux Kernel Mailing List <linux-kernel@vger.kernel.org>,
Linux OMAP Mailing List <linux-omap@vger.kernel.org>,
platform-driver-x86@vger.kernel.org,
"linux-pm@vger.kernel.org" <linux-pm@vger.kernel.org>
Subject: Re: [PATCH 1/1] thermal: core: call thermal_zone_device_update() after mode update
Date: Fri, 1 Jul 2016 13:53:31 -0700 [thread overview]
Message-ID: <20160701205329.GB7814@localhost.localdomain> (raw)
In-Reply-To: <CAJZ5v0hRosrpW50Jx3p6-yHmNFLEaHpf9htfevtunEa10Jo7Dg@mail.gmail.com>
On Thu, Jun 23, 2016 at 02:27:12PM +0200, Rafael J. Wysocki wrote:
> On Wed, Jun 22, 2016 at 7:06 AM, Eduardo Valentin <edubezval@gmail.com> wrote:
> > Because several drivers do the following pattern:
> > .set_mode()
> > ...
> > local_data->mode = new_mode;
> > thermal_zone_device_update(tz);
> >
> > makes sense to simply do the thermal_zone_device_update()
> > in thermal core, after setting the new mode.
> >
> > Also, this patch also remove deadlocks on drivers that
> > call thermal_zone_device_update() on .set_mode(),
> > as .set_mode() is now called always with tz->lock held.
>
> To me, this part of the patch is way more important than the
> optimization mentioned before.
>
> Apparently, the problem is that drivers deadlock, because the
> thermal_zone_device_update() invoked from ->set_mode() is called under
> tz->lock.
>
> So to address that problem you make the core call
> thermal_zone_device_update() after ->set_mode() outside of tz->lock
> and the drivers don't have to do it any more.
>
> Is that correct?
Yes this is correct. The optimization is simply a consequence of the bug
fix, as reported by Keerthy.
>
> Thanks,
> Rafael
next prev parent reply other threads:[~2016-07-01 20:53 UTC|newest]
Thread overview: 36+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-05-31 6:31 [PATCH 00/15] thermal: sysfs: add locking Eduardo Valentin
2016-05-31 6:31 ` [PATCH 01/15] thermal: sysfs: lock tz in type_show Eduardo Valentin
2016-05-31 6:31 ` [PATCH 02/15] thermal: sysfs: lock tz while on access to mode properties Eduardo Valentin
2016-06-07 9:08 ` Keerthy
2016-06-07 9:22 ` Keerthy
2016-06-22 2:45 ` Zhang Rui
2016-06-22 5:06 ` [PATCH 1/1] thermal: core: call thermal_zone_device_update() after mode update Eduardo Valentin
2016-06-23 12:27 ` Rafael J. Wysocki
2016-06-23 12:37 ` Keerthy
2016-07-01 20:53 ` Eduardo Valentin [this message]
2016-06-22 5:15 ` [PATCHv2 " Eduardo Valentin
2016-06-22 9:33 ` Keerthy
2016-06-22 14:36 ` Eduardo Valentin
2016-06-22 15:05 ` Eduardo Valentin
2016-06-22 14:34 ` [PATCHv3 " Eduardo Valentin
2016-06-22 15:03 ` [PATCHv4 " Eduardo Valentin
2016-06-23 4:38 ` Keerthy
2016-06-23 4:51 ` Darren Hart
2016-06-29 6:23 ` Zhang Rui
2016-07-01 20:57 ` Eduardo Valentin
2016-07-03 9:03 ` Peter Feuerer
2016-07-02 2:49 ` [PATCHv2 1/1] thermal: sysfs: lock tz while on access to mode properties Eduardo Valentin
2016-05-31 6:31 ` [PATCH 03/15] thermal: sysfs: lock tz while on trip_point_type properties Eduardo Valentin
2016-05-31 6:31 ` [PATCH 04/15] thermal: sysfs: lock tz while on trip_point_temp properties Eduardo Valentin
2016-05-31 6:31 ` [PATCH 05/15] thermal: sysfs: lock tz while on trip_point_hyst properties Eduardo Valentin
2016-05-31 6:31 ` [PATCH 06/15] thermal: sysfs: lock tz while on passive properties Eduardo Valentin
2016-05-31 6:31 ` [PATCH 07/15] thermal: sysfs: lock tz while on policy properties Eduardo Valentin
2016-05-31 6:31 ` [PATCH 08/15] thermal: sysfs: improve locking of emul_temp_store() Eduardo Valentin
2016-05-31 6:31 ` [PATCH 09/15] thermal: sysfs: lock tz when access sustainable power properties Eduardo Valentin
2016-05-31 6:31 ` [PATCH 10/15] thermal: sysfs: lock tz when access tzp properties Eduardo Valentin
2016-05-31 6:31 ` [PATCH 11/15] thermal: sysfs: lock cdev while accessing type Eduardo Valentin
2016-05-31 6:31 ` [PATCH 12/15] thermal: sysfs: lock cdev while accessing max_state Eduardo Valentin
2016-05-31 6:31 ` [PATCH 13/15] thermal: sysfs: lock cdev while accessing cur_state Eduardo Valentin
2016-05-31 6:31 ` [PATCH 14/15] thermal: sysfs: serialize access to instances Eduardo Valentin
2016-05-31 6:31 ` [PATCH 15/15] thermal: sysfs: add comments describing locking strategy Eduardo Valentin
2016-06-01 3:56 ` [PATCH 00/15] thermal: sysfs: add locking Keerthy
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