2023-03-29 09:25:42

by Wen Gong

[permalink] [raw]
Subject: [PATCH 1/2] wifi: ath11k: move update channel list from update reg worker to reg notifier

Currently ath11k call regulatory_set_wiphy_regd() in ath11k_regd_update()
to notify the reg domain change to cfg80211, and then ath11k update the
channel list to firmware by ath11k_reg_update_chan_list() immediately in
ath11k_regd_update(), they are running in two threads, it leads the channel
list data out of sync caused by muti-threads without synchronization.
cfg80211 calculate the flags of ieee80211_channel asynchronously in its
reg_work, it is calculated by the callstack below and ath11k get the
flags of ieee80211_channel in another thread without synchronization
for the channel list data.

callstack:
handle_channel_custom()
handle_band_custom()
reg_process_self_managed_hint()
reg_process_self_managed_hints()
reg_todo()

ath11k_reg_update_chan_list() need to use the flags calculated by the
reg_work, they are two thread and have no synchronization for the flags,
then ath11k_reg_update_chan_list() maybe get the wrong flags value before
the calculation finished.

The correct flow is ath11k_reg_update_chan_list() should be called after
the flags finished calculation by reg_work. reg_call_notifier() with
initiator type NL80211_REGDOM_SET_BY_DRIVER will be called by
reg_process_self_managed_hint() after the calculation finished.

So change to update channel list in ath11k_reg_notifier() for initiator
type NL80211_REGDOM_SET_BY_DRIVER, then the calculation of flags of
ieee80211_channel has already finished and ath11k_reg_update_chan_list()
will use the correct value of flags.

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 <[email protected]>
---
drivers/net/wireless/ath/ath11k/reg.c | 18 ++++++++++++------
1 file changed, 12 insertions(+), 6 deletions(-)

diff --git a/drivers/net/wireless/ath/ath11k/reg.c b/drivers/net/wireless/ath/ath11k/reg.c
index 6fae4e61ede7..f50740219202 100644
--- a/drivers/net/wireless/ath/ath11k/reg.c
+++ b/drivers/net/wireless/ath/ath11k/reg.c
@@ -55,6 +55,17 @@ ath11k_reg_notifier(struct wiphy *wiphy, struct regulatory_request *request)
ath11k_dbg(ar->ab, ATH11K_DBG_REG,
"Regulatory Notification received for %s\n", wiphy_name(wiphy));

+ if ((request->initiator == NL80211_REGDOM_SET_BY_DRIVER) &&
+ (ar->state == ATH11K_STATE_ON)) {
+ ath11k_dbg(ar->ab, ATH11K_DBG_REG,
+ "dynamically updated by driver\n");
+ ret = ath11k_reg_update_chan_list(ar, true);
+ if (ret)
+ ath11k_warn(ar->ab, "failed to update channel list: %d\n", ret);
+
+ return;
+ }
+
/* Currently supporting only General User Hints. Cell base user
* hints to be handled later.
* Hints from other sources like Core, Beacons are not expected for
@@ -294,12 +305,6 @@ int ath11k_regd_update(struct ath11k *ar)
if (ret)
goto err;

- if (ar->state == ATH11K_STATE_ON) {
- ret = ath11k_reg_update_chan_list(ar, true);
- if (ret)
- goto err;
- }
-
return 0;
err:
ath11k_warn(ab, "failed to perform regd update : %d\n", ret);
@@ -743,6 +748,7 @@ void ath11k_regd_update_work(struct work_struct *work)
void ath11k_reg_init(struct ath11k *ar)
{
ar->hw->wiphy->regulatory_flags = REGULATORY_WIPHY_SELF_MANAGED;
+ ar->hw->wiphy->flags |= WIPHY_FLAG_NOTIFY_REGDOM_BY_DRIVER;
ar->hw->wiphy->reg_notifier = ath11k_reg_notifier;
}

--
2.31.1