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References: <20230303161910.3195805-1-srinivas.pandruvada@linux.intel.com> <ZAJB7qTK81T7Zau4@kroah.com>
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From:   "Rafael J. Wysocki" <rafael@kernel.org>
Date:   Fri, 3 Mar 2023 20:11:20 +0100
Message-ID: <CAJZ5v0g84guSv1MCjwJWbhO1-RFZ4bpaWFy_Mcusra3N=mjdZQ@mail.gmail.com>
Subject: Re: [PATCH] thermal: int340x: processor_thermal: Fix deadlock
To:     Greg KH <gregkh@linuxfoundation.org>
Cc:     Srinivas Pandruvada <srinivas.pandruvada@linux.intel.com>,
        rafael@kernel.org, rui.zhang@intel.com, daniel.lezcano@linaro.org,
        linux-pm@vger.kernel.org, linux-kernel@vger.kernel.org,
        Srinivas Pandruvada <srinivas.pandruvada@intel.com>,
        stable@vger.kernel.org
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On Fri, Mar 3, 2023 at 7:52 PM Greg KH <gregkh@linuxfoundation.org> wrote:
>
> On Fri, Mar 03, 2023 at 08:19:09AM -0800, Srinivas Pandruvada wrote:
> > From: Srinivas Pandruvada <srinivas.pandruvada@intel.com>
> >
> > When user space updates the trip point there is a deadlock, which results
> > in caller gets blocked forever.
> >
> > Commit 05eeee2b51b4 ("thermal/core: Protect sysfs accesses to thermal
> > operations with thermal zone mutex"), added a mutex for tz->lock in the
> > function trip_point_temp_store(). Hence, trip set callback() can't
> > call any thermal zone API as they are protected with the same mutex lock.
> >
> > The callback here calling thermal_zone_device_enable(), which will result
> > in deadlock.
> >
> > Move the thermal_zone_device_enable() to proc_thermal_pci_probe() to
> > avoid this deadlock.
> >
> > Signed-off-by: Srinivas Pandruvada <srinivas.pandruvada@intel.com>
> > Cc: stable@vger.kernel.org
> > ---
> > The commit which caused this issue was added during v6.2 cycle.
>
> What commit exactly?  Always list that as a Fixes: tag if you know this.

It's there in the changelog above.

I'll add a Fixes: tag to this one when applying it.

Cheers!