Baochen Qiang d78c8b7131 wifi: ath11k: Fix deadlock during WoWLAN suspend
We are seeing system hangs during WoWLAN suspend, and get below
two stacks:

Stack1:
[ffffb02cc1557b20] __schedule at ffffffff8bb10860
[ffffb02cc1557ba8] schedule at ffffffff8bb10f24
[ffffb02cc1557bb8] schedule_timeout at ffffffff8bb16d88
[ffffb02cc1557c30] wait_for_completion at ffffffff8bb11778
[ffffb02cc1557c78] __flush_work at ffffffff8b0b30cd
[ffffb02cc1557cf0] __cancel_work_timer at ffffffff8b0b33ad
[ffffb02cc1557d60] ath11k_mac_drain_tx at ffffffffc0c1f0ca [ath11k]
[ffffb02cc1557d70] ath11k_wow_op_suspend at ffffffffc0c5201e [ath11k]
[ffffb02cc1557da8] __ieee80211_suspend at ffffffffc11e2bd3 [mac80211]
[ffffb02cc1557dd8] wiphy_suspend at ffffffffc0f901ac [cfg80211]
[ffffb02cc1557e08] dpm_run_callback at ffffffff8b75118a
[ffffb02cc1557e38] __device_suspend at ffffffff8b751630
[ffffb02cc1557e70] async_suspend at ffffffff8b7519ea
[ffffb02cc1557e88] async_run_entry_fn at ffffffff8b0bf4ce
[ffffb02cc1557ea8] process_one_work at ffffffff8b0b1a24
[ffffb02cc1557ee0] worker_thread at ffffffff8b0b1c4a
[ffffb02cc1557f18] kthread at ffffffff8b0b9cb8
[ffffb02cc1557f50] ret_from_fork at ffffffff8b001d32

Stack2:
[ffffb02cc00b7d18] __schedule at ffffffff8bb10860
[ffffb02cc00b7da0] schedule at ffffffff8bb10f24
[ffffb02cc00b7db0] schedule_preempt_disabled at ffffffff8bb112b4
[ffffb02cc00b7db8] __mutex_lock at ffffffff8bb127ea
[ffffb02cc00b7e38] ath11k_mgmt_over_wmi_tx_work at ffffffffc0c1aa44 [ath11k]
[ffffb02cc00b7ea8] process_one_work at ffffffff8b0b1a24
[ffffb02cc00b7ee0] worker_thread at ffffffff8b0b1c4a
[ffffb02cc00b7f18] kthread at ffffffff8b0b9cb8
[ffffb02cc00b7f50] ret_from_fork at ffffffff8b001d32

From the first stack, ath11k_mac_drain_tx calls
cancel_work_sync(&ar->wmi_mgmt_tx_work) and waits all packets to be sent
out or dropped. However, we find from Stack2 that this work item is blocked
because ar->conf_mutex is already held by ath11k_wow_op_suspend.

Fix this issue by moving ath11k_mac_wait_tx_complete to the start of
ath11k_wow_op_suspend where ar->conf_mutex has not been acquired. And
this change also makes the logic in ath11k_wow_op_suspend match the
logic in ath11k_mac_op_start and ath11k_mac_op_stop.

Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3

Signed-off-by: Baochen Qiang <quic_bqiang@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20220919021435.2459-1-quic_bqiang@quicinc.com
2022-09-26 12:41:04 +03:00
2022-08-21 10:06:28 -07:00
2022-08-21 17:32:54 -07:00

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.
Description
No description provided
Readme 7.9 GiB
Languages
C 97.7%
Assembly 1.6%
Makefile 0.3%
Perl 0.1%