0f2aa38659
[ Upstream commit a9fd0953fa4a62887306be28641b4b0809f3b2fd ]
Leaving dev_init_lock mutex locked in probe causes BUG and a WARNING when
kernel is compiled with CONFIG_PROVE_LOCKING. Convert mutex to completion
which silences those warnings and improves code readability.
Fix below errors when connecting the USB WiFi dongle:
brcmfmac: brcmf_fw_alloc_request: using brcm/brcmfmac43143 for chip BCM43143/2
BUG: workqueue leaked lock or atomic: kworker/0:2/0x00000000/434
last function: hub_event
1 lock held by kworker/0:2/434:
#0: 18d5dcdf (&devinfo->dev_init_lock){+.+.}, at: brcmf_usb_probe+0x78/0x550 [brcmfmac]
CPU: 0 PID: 434 Comm: kworker/0:2 Not tainted 4.19.23-00084-g454a789-dirty #123
Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
Workqueue: usb_hub_wq hub_event
[<8011237c>] (unwind_backtrace) from [<8010d74c>] (show_stack+0x10/0x14)
[<8010d74c>] (show_stack) from [<809c4324>] (dump_stack+0xa8/0xd4)
[<809c4324>] (dump_stack) from [<8014195c>] (process_one_work+0x710/0x808)
[<8014195c>] (process_one_work) from [<80141a80>] (worker_thread+0x2c/0x564)
[<80141a80>] (worker_thread) from [<80147bcc>] (kthread+0x13c/0x16c)
[<80147bcc>] (kthread) from [<801010b4>] (ret_from_fork+0x14/0x20)
Exception stack(0xed1d9fb0 to 0xed1d9ff8)
9fa0: 00000000 00000000 00000000 00000000
9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
9fe0: 00000000 00000000 00000000 00000000 00000013 00000000
======================================================
WARNING: possible circular locking dependency detected
4.19.23-00084-g454a789-dirty #123 Not tainted
------------------------------------------------------
kworker/0:2/434 is trying to acquire lock:
e29cf799 ((wq_completion)"events"){+.+.}, at: process_one_work+0x174/0x808
but task is already holding lock:
18d5dcdf (&devinfo->dev_init_lock){+.+.}, at: brcmf_usb_probe+0x78/0x550 [brcmfmac]
which lock already depends on the new lock.
the existing dependency chain (in reverse order) is:
-> #2 (&devinfo->dev_init_lock){+.+.}:
mutex_lock_nested+0x1c/0x24
brcmf_usb_probe+0x78/0x550 [brcmfmac]
usb_probe_interface+0xc0/0x1bc
really_probe+0x228/0x2c0
__driver_attach+0xe4/0xe8
bus_for_each_dev+0x68/0xb4
bus_add_driver+0x19c/0x214
driver_register+0x78/0x110
usb_register_driver+0x84/0x148
process_one_work+0x228/0x808
worker_thread+0x2c/0x564
kthread+0x13c/0x16c
ret_from_fork+0x14/0x20
(null)
-> #1 (brcmf_driver_work){+.+.}:
worker_thread+0x2c/0x564
kthread+0x13c/0x16c
ret_from_fork+0x14/0x20
(null)
-> #0 ((wq_completion)"events"){+.+.}:
process_one_work+0x1b8/0x808
worker_thread+0x2c/0x564
kthread+0x13c/0x16c
ret_from_fork+0x14/0x20
(null)
other info that might help us debug this:
Chain exists of:
(wq_completion)"events" --> brcmf_driver_work --> &devinfo->dev_init_lock
Possible unsafe locking scenario:
CPU0 CPU1
---- ----
lock(&devinfo->dev_init_lock);
lock(brcmf_driver_work);
lock(&devinfo->dev_init_lock);
lock((wq_completion)"events");
*** DEADLOCK ***
1 lock held by kworker/0:2/434:
#0: 18d5dcdf (&devinfo->dev_init_lock){+.+.}, at: brcmf_usb_probe+0x78/0x550 [brcmfmac]
stack backtrace:
CPU: 0 PID: 434 Comm: kworker/0:2 Not tainted 4.19.23-00084-g454a789-dirty #123
Hardware name: Freescale i.MX6 Quad/DualLite (Device Tree)
Workqueue: events request_firmware_work_func
[<8011237c>] (unwind_backtrace) from [<8010d74c>] (show_stack+0x10/0x14)
[<8010d74c>] (show_stack) from [<809c4324>] (dump_stack+0xa8/0xd4)
[<809c4324>] (dump_stack) from [<80172838>] (print_circular_bug+0x210/0x330)
[<80172838>] (print_circular_bug) from [<80175940>] (__lock_acquire+0x160c/0x1a30)
[<80175940>] (__lock_acquire) from [<8017671c>] (lock_acquire+0xe0/0x268)
[<8017671c>] (lock_acquire) from [<80141404>] (process_one_work+0x1b8/0x808)
[<80141404>] (process_one_work) from [<80141a80>] (worker_thread+0x2c/0x564)
[<80141a80>] (worker_thread) from [<80147bcc>] (kthread+0x13c/0x16c)
[<80147bcc>] (kthread) from [<801010b4>] (ret_from_fork+0x14/0x20)
Exception stack(0xed1d9fb0 to 0xed1d9ff8)
9fa0: 00000000 00000000 00000000 00000000
9fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
9fe0: 00000000 00000000 00000000 00000000 00000013 00000000
Signed-off-by: Piotr Figiel <p.figiel@camlintechnologies.com>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
Linux kernel ============ This file was moved to Documentation/admin-guide/README.rst Please notice that there are several guides for kernel developers and users. These guides can be rendered in a number of formats, like HTML and PDF. In order to build the documentation, use ``make htmldocs`` or ``make pdfdocs``. There are various text files in the Documentation/ subdirectory, several of them using the Restructured Text markup notation. See Documentation/00-INDEX for a list of what is contained in each file. 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.