From: Naresh Kamboju <naresh.kamboju@linaro.org>
To: Marek Szyprowski <m.szyprowski@samsung.com>
Cc: David Collins <collinsd@codeaurora.org>,
Mark Brown <broonie@kernel.org>,
Liam Girdwood <lgirdwood@gmail.com>,
Krzysztof Kozlowski <krzk@kernel.org>,
Bartlomiej Zolnierkiewicz <b.zolnierkie@samsung.com>,
linux-arm-msm <linux-arm-msm@vger.kernel.org>,
open list <linux-kernel@vger.kernel.org>,
Linux Samsung SOC <linux-samsung-soc@vger.kernel.org>,
lkft-triage@lists.linaro.org
Subject: Re: [PATCH] regulator: core: avoid regulator_resolve_supply() race condition
Date: Mon, 18 Jan 2021 17:11:05 +0530 [thread overview]
Message-ID: <CA+G9fYunK_2h3-pHtZT_+56Xf8b=M-8Q9GnTsCJ3KxVaJULorA@mail.gmail.com> (raw)
In-Reply-To: <e512ee85-7fa6-e5fe-eb30-f088bb83cf23@samsung.com>
Hi,
On Wed, 13 Jan 2021 at 03:21, Marek Szyprowski <m.szyprowski@samsung.com> wrote:
>
> Hi,
>
<trim>
>
> This patch landed in linux next-20210112 as commit eaa7995c529b
> ("regulator: core: avoid regulator_resolve_supply() race condition"). I
> found that it triggers a following lockdep warning during the DWC3
> driver registration on some Exynos based boards (this log is from
> Samsung Exynos5420-based Peach-Pit board):
>
> ======================================================
> WARNING: possible circular locking dependency detected
> 5.11.0-rc1-00008-geaa7995c529b #10095 Not tainted
> ------------------------------------------------------
> swapper/0/1 is trying to acquire lock:
> c12e1b80 (regulator_list_mutex){+.+.}-{3:3}, at:
> regulator_lock_dependent+0x4c/0x2b0
>
> but task is already holding lock:
> df7190c0 (regulator_ww_class_mutex){+.+.}-{3:3}, at:
> regulator_resolve_supply+0x44/0x318
LKFT testing also found this lockdep warning on
arm64 - hi6220-hikey while booting.
[ 0.635532] WARNING: possible recursive locking detected
[ 0.635558] 5.11.0-rc3-next-20210118 #1 Not tainted
[ 0.635585] --------------------------------------------
[ 0.635611] swapper/0/1 is trying to acquire lock:
[ 0.635636] ffff000000a13158
(regulator_ww_class_mutex){+.+.}-{3:3}, at:
regulator_lock_recursive+0x9c/0x1e8
[ 0.635721]
[ 0.635721] but task is already holding lock:
[ 0.635749] ffff000000a13958
(regulator_ww_class_mutex){+.+.}-{3:3}, at:
regulator_resolve_supply+0x70/0x2f0
[ 0.635817]
[ 0.635817] other info that might help us debug this:
[ 0.635847] Possible unsafe locking scenario:
[ 0.635847]
[ 0.635875] CPU0
[ 0.635892] ----
[ 0.635909] lock(regulator_ww_class_mutex);
[ 0.635942] lock(regulator_ww_class_mutex);
[ 0.635974]
[ 0.635974] *** DEADLOCK ***
[ 0.635974]
[ 0.636002] May be due to missing lock nesting notation
[ 0.636002]
[ 0.636033] 4 locks held by swapper/0/1:
[ 0.636057] #0: ffff000000a02988 (&dev->mutex){....}-{3:3}, at:
__device_driver_lock+0x38/0x70
[ 0.636131] #1: ffff000000a13958
(regulator_ww_class_mutex){+.+.}-{3:3}, at:
regulator_resolve_supply+0x70/0x2f0
[ 0.636205] #2: ffff800012b102c0
(regulator_list_mutex){+.+.}-{3:3}, at:
regulator_lock_dependent+0x5c/0x290
[ 0.636280] #3: ffff8000137e3918
(regulator_ww_class_acquire){+.+.}-{0:0}, at:
regulator_enable+0x40/0xe0
[ 0.636352]
[ 0.636352] stack backtrace:
[ 0.636378] CPU: 0 PID: 1 Comm: swapper/0 Not tainted
5.11.0-rc3-next-20210118 #1
[ 0.636415] Hardware name: HiKey Development Board (DT)
[ 0.636443] Call trace:
[ 0.636460] dump_backtrace+0x0/0x1f0
[ 0.636490] show_stack+0x2c/0x80
[ 0.636516] dump_stack+0xf8/0x160
[ 0.636543] __lock_acquire+0xa3c/0x1718
[ 0.636571] lock_acquire+0x3d8/0x4f0
[ 0.636596] __ww_mutex_lock.constprop.14+0xbc/0xf68
[ 0.636628] ww_mutex_lock+0x6c/0x3e8
[ 0.636653] regulator_lock_recursive+0x9c/0x1e8
[ 0.636683] regulator_lock_dependent+0x198/0x290
[ 0.636713] regulator_enable+0x40/0xe0
[ 0.636739] regulator_resolve_supply+0x1e8/0x2f0
[ 0.636767] regulator_register_resolve_supply+0x24/0x80
[ 0.636797] class_for_each_device+0x78/0xf8
[ 0.636825] regulator_register+0x840/0xbb0
[ 0.636851] devm_regulator_register+0x50/0xa8
[ 0.636879] reg_fixed_voltage_probe+0x224/0x410
[ 0.636908] platform_probe+0x6c/0xd8
[ 0.636932] really_probe+0x2b8/0x520
[ 0.636960] driver_probe_device+0xf4/0x168
[ 0.636988] device_driver_attach+0x74/0x98
[ 0.637014] __driver_attach+0xc4/0x178
[ 0.637039] bus_for_each_dev+0x84/0xd8
[ 0.637066] driver_attach+0x30/0x40
[ 0.637092] bus_add_driver+0x170/0x258
[ 0.637119] driver_register+0x64/0x118
[ 0.637144] __platform_driver_register+0x34/0x40
[ 0.637172] regulator_fixed_voltage_init+0x20/0x28
[ 0.637205] do_one_initcall+0x94/0x4a0
[ 0.637231] kernel_init_freeable+0x2f0/0x344
[ 0.637261] kernel_init+0x18/0x120
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Full boot log here:
https://qa-reports.linaro.org/lkft/linux-next-master/build/next-20210118/testrun/3771538/suite/linux-log-parser/test/check-kernel-warning-2159912/log
metadata:
git branch: master
git repo: https://git.kernel.org/pub/scm/linux/kernel/git/next/linux-next.git
git describe: next-20210112
kernel-config:
http://snapshots.linaro.org/openembedded/lkft/lkft/sumo/hikey/lkft/linux-next/935/config
--
Linaro LKFT
https://lkft.linaro.org
next prev parent reply other threads:[~2021-01-18 18:25 UTC|newest]
Thread overview: 10+ messages / expand[flat|nested] mbox.gz Atom feed top
2021-01-08 1:16 [PATCH] regulator: core: avoid regulator_resolve_supply() race condition David Collins
2021-01-11 16:28 ` Mark Brown
[not found] ` <CGME20210112213419eucas1p24231e4d0ac11c31184f2f8f3f20cbd9d@eucas1p2.samsung.com>
2021-01-12 21:34 ` Marek Szyprowski
2021-01-18 11:41 ` Naresh Kamboju [this message]
2021-01-18 20:49 ` Mark Brown
2021-01-21 9:41 ` Marek Szyprowski
2021-01-21 15:44 ` Mark Brown
2021-01-21 20:30 ` Marek Szyprowski
2021-01-23 1:54 ` David Collins
2021-03-01 19:59 ` patchwork-bot+linux-arm-msm
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