bcafcb959a
The ieee80211_ops::sta_rc_update must be atomic, because ieee80211_chan_bw_change() holds rcu_read lock while calling drv_sta_rc_update(), so create a work to do original things. Voluntary context switch within RCU read-side critical section! WARNING: CPU: 0 PID: 4621 at kernel/rcu/tree_plugin.h:318 rcu_note_context_switch+0x571/0x5d0 CPU: 0 PID: 4621 Comm: kworker/u16:2 Tainted: G W OE Workqueue: phy3 ieee80211_chswitch_work [mac80211] RIP: 0010:rcu_note_context_switch+0x571/0x5d0 Call Trace: <TASK> __schedule+0xb0/0x1460 ? __mod_timer+0x116/0x360 schedule+0x5a/0xc0 schedule_timeout+0x87/0x150 ? trace_raw_output_tick_stop+0x60/0x60 wait_for_completion_timeout+0x7b/0x140 usb_start_wait_urb+0x82/0x160 [usbcore usb_control_msg+0xe3/0x140 [usbcore rtw_usb_read+0x88/0xe0 [rtw_usb rtw_usb_read8+0xf/0x10 [rtw_usb rtw_fw_send_h2c_command+0xa0/0x170 [rtw_core rtw_fw_send_ra_info+0xc9/0xf0 [rtw_core drv_sta_rc_update+0x7c/0x160 [mac80211 ieee80211_chan_bw_change+0xfb/0x110 [mac80211 ieee80211_change_chanctx+0x38/0x130 [mac80211 ieee80211_vif_use_reserved_switch+0x34e/0x900 [mac80211 ieee80211_link_use_reserved_context+0x88/0xe0 [mac80211 ieee80211_chswitch_work+0x95/0x170 [mac80211 process_one_work+0x201/0x410 worker_thread+0x4a/0x3b0 ? process_one_work+0x410/0x410 kthread+0xe1/0x110 ? kthread_complete_and_exit+0x20/0x20 ret_from_fork+0x1f/0x30 </TASK> Cc: stable@vger.kernel.org Fixes: c1edc86472fc ("rtw88: add ieee80211:sta_rc_update ops") Reported-by: Larry Finger <Larry.Finger@lwfinger.net> Link: https://lore.kernel.org/linux-wireless/f1e31e8e-f84e-3791-50fb-663a83c5c6e9@lwfinger.net/T/#t Signed-off-by: Ping-Ke Shih <pkshih@realtek.com> Tested-by: Larry Finger <Larry.Finger@lwfinger.net> Signed-off-by: Kalle Valo <kvalo@kernel.org> Link: https://lore.kernel.org/r/20230508085429.46653-1-pkshih@realtek.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.