[PATCHv2] wifi: ath11k: Fix race condition with htt_ppdu_stats_info

[Kalle Valo]

Karthikeyan Kathirvel <quic_kathirve at quicinc.com> wrote:

> The below crash happens when running the traffic with multiple clients
> 
> Crash Signature : Unable to handle kernel paging request at
> virtual address ffffffd700970918 During the crash, PC points to
> "ieee80211_tx_rate_update+0x30/0x68 [mac80211]"
> LR points to "ath11k_dp_htt_htc_t2h_msg_handler+0x5a8/0x8a0 [ath11k]".
> 
> ppdu_stats_info is allocated and accessed from event callback via copy
> engine tasklet, this has a problem when freeing it from ath11k_mac_op_stop.
> 
> Add spin lock to protect htt_ppdu_stats_info and to avoid race condition
> when accessing it from ath11k_mac_op_stop.
> 
> Tested-on : IPQ8074 hw2.0 AHB WLAN.HK.2.7.0.1-01744-QCAHKSWPL_SILICONZ-1
> 
> Signed-off-by: Govindaraj Saminathan <quic_gsaminat at quicinc.com>
> Co-developed-by: Karthikeyan Kathirvel <quic_kathirve at quicinc.com>
> Signed-off-by: Karthikeyan Kathirvel <quic_kathirve at quicinc.com>
> Signed-off-by: Kalle Valo <quic_kvalo at quicinc.com>

This patch added a new checkpatch warning:

drivers/net/wireless/ath/ath11k/dp_rx.c:1542: braces {} are not necessary for single statement blocks

I fixed it in the pending branch.

-- 
https://patchwork.kernel.org/project/linux-wireless/patch/20221124071104.22506-1-quic_kathirve@quicinc.com/

https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches