Re: [PATCH v2 1/2] wifi: ath11k: move update channel list from update reg worker to reg notifier

[Jeff Johnson <quic_jjohnson@xxxxxxxxxxx>]

On 9/5/2024 8:31 PM, Kang Yang wrote:
> From: Wen Gong <quic_wgong@xxxxxxxxxxx>
> 
> Currently ath11k call regulatory_set_wiphy_regd() in ath11k_regd_update()
> to notify the reg domain change to cfg80211 and update channel list by
> reg_work, then ath11k immediately update channel list to firmware by
> ath11k_reg_update_chan_list(). 
> 
> callstack:
> ath11k_regd_update
> ->regulatory_set_wiphy_regd
>            -> schedule_work(&reg_work)
> -> ath11k_reg_update_chan_list
> 
> They are running in two threads, it leads the channel list data out of
> sync caused by muti-threads without synchronization. At this time,
> ath11k may update wrong channel list to firmware because the reg_work
> still running or even hasn't started yet.
> 
> The correct flow is after reg_work update the channel list according to
> new reg domain, ath11k call ath11k_reg_update_chan_list() and update the
> new channel list to firmware.
> 
> reg_call_notifier()(finally it will call ath11k_reg_notifier()) will be
> called to by reg_work to notify ath11k when it finishes the channel
> list update. So at this time, call ath11k_reg_update_chan_list() in
> reg_call_notifier() with initiator type NL80211_REGDOM_SET_BY_DRIVER.
> Then ath11k_reg_update_chan_list() will use the correct channel list.
> 
> Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3
> 
> Fixes: f45cb6b29cd3 ("wifi: ath11k: avoid deadlock during regulatory update in ath11k_regd_update()")
> Signed-off-by: Wen Gong <quic_wgong@xxxxxxxxxxx>
> Signed-off-by: Kang Yang <quic_kangyang@xxxxxxxxxxx>
Acked-by: Jeff Johnson <quic_jjohnson@xxxxxxxxxxx>