[PATCH] wifi: ath12k: set the regdomain before registering the wiphy

["François Roux" <franzelfranzel@gmail.com>]

ath12k marks its wiphy as REGULATORY_WIPHY_SELF_MANAGED, but it applies
the regdomain received from the firmware only after
ieee80211_register_hw(). cfg80211 announces the new wiphy to userspace
during registration, so a GET_REG request sent in that window finds a
self-managed wiphy without a regdomain:

  WARNING: net/wireless/nl80211.c:10828 at nl80211_get_reg_do+0x1d0/0x1fc [cfg80211], CPU#5: iwd/721

iwd queries the regdomain of each new wiphy right away, so this shows up
at boot. On a Microsoft Surface Pro 11 (WCN7850) it happened in 3 of 4
boots.

Apply the boot-time regdomain before ieee80211_register_hw().
regulatory_set_wiphy_regd() only queues it. cfg80211 then applies it in
wiphy_regulatory_register(), which runs under the RTNL before
wiphy_register() returns. nl80211_get_reg_do() also takes the
RTNL, so userspace can no longer see the wiphy without a regdomain.

The regdomain update no longer needs to unregister the hw on failure,
so drop that error path.

Tested on a Surface Pro 11 (WCN7850 hw2.0, WLAN.HMT.1.1.c7-00108) with
next-20260929:
- without this patch, every driver unbind/bind triggers the warning
  (12 warnings over 6 cycles);
- with it, there is no warning over two boots, two module reloads and
  17 unbind/bind cycles, and Wi-Fi connects each time;
- with CONFIG_ATH_REG_DYNAMIC_USER_REG_HINTS and the user regdomain set
  to CH, the wiphy ends up with CH after each of 4 unbind/bind cycles,
  with or without this patch. The user hint handling added by commit
  906619a00967 ("wifi: ath12k: handle regulatory hints during mac
  registration") still works.

Link: https://lore.kernel.org/all/20261006161744.3804-1-franzelfranzel@gmail.com/
Assisted-by: LLM
Signed-off-by: François Roux <franzelfranzel@gmail.com>
---
 drivers/net/wireless/ath/ath12k/mac.c | 25 ++++++++++++-------------
 1 file changed, 12 insertions(+), 13 deletions(-)

diff --git a/drivers/net/wireless/ath/ath12k/mac.c b/drivers/net/wireless/ath/ath12k/mac.c
index 196b80721..1208c1698 100644
--- a/drivers/net/wireless/ath/ath12k/mac.c
+++ b/drivers/net/wireless/ath/ath12k/mac.c
@@ -15041,6 +15041,18 @@ static int ath12k_mac_hw_register(struct ath12k_hw *ah)
 	for_each_ar(ah, ar, i)
 		complete_all(&ar->regd_update_completed);
 
+	/* Apply the regd received during initialization before registering
+	 * the wiphy. It is self-managed, so userspace may ask for its regd as
+	 * soon as it shows up, and cfg80211 expects one to be there.
+	 */
+	for_each_ar(ah, ar, i) {
+		ret = ath12k_regd_update(ar, true);
+		if (ret) {
+			ath12k_err(ar->ab, "ath12k regd update failed: %d\n", ret);
+			goto err_cleanup_if_combs;
+		}
+	}
+
 	ret = ieee80211_register_hw(hw);
 	if (ret) {
 		ath12k_err(ab, "ieee80211 registration failed: %d\n", ret);
@@ -15058,13 +15070,6 @@ static int ath12k_mac_hw_register(struct ath12k_hw *ah)
 	for_each_ar(ah, ar, i) {
 		struct ath12k_base *this_ab = ar->ab;
 
-		/* Apply the regd received during initialization */
-		ret = ath12k_regd_update(ar, true);
-		if (ret) {
-			ath12k_err(this_ab, "ath12k regd update failed: %d\n", ret);
-			goto err_unregister_hw;
-		}
-
 		if (this_ab->hw_params->current_cc_support) {
 			struct wmi_set_current_country_arg current_cc = {};
 			struct ieee80211_regdomain *default_regd;
@@ -15105,12 +15110,6 @@ static int ath12k_mac_hw_register(struct ath12k_hw *ah)
 
 	return 0;
 
-err_unregister_hw:
-	for_each_ar(ah, ar, i)
-		ath12k_debugfs_unregister(ar);
-
-	ieee80211_unregister_hw(hw);
-
 err_cleanup_if_combs:
 	ath12k_mac_cleanup_iface_combinations(ah);
 

base-commit: 6474fa070f2b8013b4b87350b775b8c3be6e8aac
-- 
2.56.0