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46cb2dc1b0
[ Upstream commit 953e549471cabc9d4980f1da2e9fa79f4c23da06 ]
Lockdep gives a false positive splat as it can't distinguish the lock
which is taken by different IRQ descriptors from different IRQ chips
that are organized in a way of a hierarchy:
======================================================
WARNING: possible circular locking dependency detected
6.12.0-rc5-next-20241101-00148-g9fabf8160b53 #562 Tainted: G W
------------------------------------------------------
modprobe/141 is trying to acquire lock:
ffff899446947868 (intel_soc_pmic_bxtwc:502:(&bxtwc_regmap_config)->lock){+.+.}-{4:4}, at: regmap_update_bits_base+0x33/0x90
but task is already holding lock:
ffff899446947c68 (&d->lock){+.+.}-{4:4}, at: __setup_irq+0x682/0x790
which lock already depends on the new lock.
-> #3 (&d->lock){+.+.}-{4:4}:
-> #2 (&desc->request_mutex){+.+.}-{4:4}:
-> #1 (ipclock){+.+.}-{4:4}:
-> #0 (intel_soc_pmic_bxtwc:502:(&bxtwc_regmap_config)->lock){+.+.}-{4:4}:
Chain exists of:
intel_soc_pmic_bxtwc:502:(&bxtwc_regmap_config)->lock --> &desc->request_mutex --> &d->lock
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&d->lock);
lock(&desc->request_mutex);
lock(&d->lock);
lock(intel_soc_pmic_bxtwc:502:(&bxtwc_regmap_config)->lock);
*** DEADLOCK ***
3 locks held by modprobe/141:
#0: ffff8994419368f8 (&dev->mutex){....}-{4:4}, at: __driver_attach+0xf6/0x250
#1: ffff89944690b250 (&desc->request_mutex){+.+.}-{4:4}, at: __setup_irq+0x1a2/0x790
#2: ffff899446947c68 (&d->lock){+.+.}-{4:4}, at: __setup_irq+0x682/0x790
Set a lockdep class when we map the IRQ so that it doesn't warn about
a lockdep bug that doesn't exist.
Fixes: 4af8be67fd ("regmap: Convert regmap_irq to use irq_domain")
Signed-off-by: Andy Shevchenko <andriy.shevchenko@linux.intel.com>
Link: https://patch.msgid.link/20241101165553.4055617-1-andriy.shevchenko@linux.intel.com
Signed-off-by: Mark Brown <broonie@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel
============
There are several guides for kernel developers and users. These guides can
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In order to build the documentation, use ``make htmldocs`` or
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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.