Linux kernel
============
There are several guides for kernel developers and users. These guides can
be rendered in a number of formats, like HTML and PDF. Please read
Documentation/admin-guide/README.rst first.
In order to build the documentation, use ``make htmldocs`` or
``make pdfdocs``. The formatted documentation can also be read online at:
https://www.kernel.org/doc/html/latest/
There are various text files in the Documentation/ subdirectory,
several of them using the Restructured Text markup notation.
Please read the Documentation/process/changes.rst file, as it contains the
requirements for building and running the kernel, and information about
the problems which may result by upgrading your kernel.
Johan Hovold
authored
The thermal-zone-device lock is held by core when setting trip points
and the driver takes its chip lock in the corresponding callback.
Fetching the thermal trip points using thermal_zone_get_trip() also
involves taking the thermal-zone-device lock, which means that the chip
lock can not be held when doing so.
Drop the chip lock temporarily during probe to avoid the lock inversion
that was detected by lockdep:
======================================================
WARNING: possible circular locking dependency detected
6.1.0-next-20221213 #122 Not tainted
------------------------------------------------------
systemd-udevd/264 is trying to acquire lock:
ffff741e444a0920 (&chip->lock){+.+.}-{3:3}, at: qpnp_tm_get_temp+0xb4/0x1b0 [qcom_spmi_temp_alarm]
but task is already holding lock:
ffff741e44341618 (&tz->lock){+.+.}-{3:3}, at: thermal_zone_device_update+0x2c/0x70
which lock already depends on the new lock.
Fixes: 78c3e2429be8 ("thermal/drivers/qcom: Use generic thermal_zone_get_trip() function")
Signed-off-by: Johan Hovold <johan+linaro@kernel.org>
Link: https://lore.kernel.org/r/20221214131617.2447-5-johan+linaro@kernel.org
Signed-off-by: Daniel Lezcano <daniel.lezcano@kernel.org>