f1a0898b5d
Lockdep on 6.4-rc on ThinkPad X1 Carbon 5th says ===================================================== WARNING: SOFTIRQ-safe -> SOFTIRQ-unsafe lock order detected 6.4.0-rc5 #1 Not tainted ----------------------------------------------------- kworker/3:1/49 [HC0[0]:SC0[4]:HE1:SE0] is trying to acquire: ffff8881066fa368 (&mvm_sta->deflink.lq_sta.rs_drv.pers.lock){+.+.}-{2:2}, at: rs_drv_get_rate+0x46/0xe7 and this task is already holding: ffff8881066f80a8 (&sta->rate_ctrl_lock){+.-.}-{2:2}, at: rate_control_get_rate+0xbd/0x126 which would create a new lock dependency: (&sta->rate_ctrl_lock){+.-.}-{2:2} -> (&mvm_sta->deflink.lq_sta.rs_drv.pers.lock){+.+.}-{2:2} but this new dependency connects a SOFTIRQ-irq-safe lock: (&sta->rate_ctrl_lock){+.-.}-{2:2} etc. etc. etc. Changing the spin_lock() in rs_drv_get_rate() to spin_lock_bh() was not enough to pacify lockdep, but changing them all on pers.lock has worked. Fixes: a8938bc881d2 ("wifi: iwlwifi: mvm: Add locking to the rate read flow") Signed-off-by: Hugh Dickins <hughd@google.com> Link: https://lore.kernel.org/r/79ffcc22-9775-cb6d-3ffd-1a517c40beef@google.com Signed-off-by: Johannes Berg <johannes.berg@intel.com>
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.