8198950ccb
Deadlock is easily happened while shutdown wlan interface such as run "ifconfig wlan0 down". The reason is because when ar->regd_update_work is ran, it will call wiphy_lock(ar->hw->wiphy) in function ath12k_regd_update() which is running in workqueue of ieee80211_local queued by ieee80211_queue_work(). Another thread from "ifconfig wlan0 down" will also accuqire the lock by wiphy_lock(sdata->local->hw.wiphy) in function ieee80211_stop(), and then it call ieee80211_stop_device() to flush_workqueue(local->workqueue), this will wait the workqueue of ieee80211_local finished. Then deadlock will happen easily if the two thread run meanwhile. Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0-03427-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1.15378.4 Signed-off-by: Wen Gong <quic_wgong@quicinc.com> Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com> Link: https://lore.kernel.org/r/20230718024724.29120-1-quic_wgong@quicinc.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.