[PATCH ath-next] wifi: ath12k: bring DFS support back for WCN7850

[Baochen Qiang]

Due to the restrict in MAC80211 that DFS (Dynamic Frequency Selection)
can't be enabled on multiple channels, commit 176f3009ae59 ("wifi: ath12k:
support 2 channels for single pdev device") removes DFS support in order
to support 2 channels concurrently, making AP mode not working on DFS
channels [1].

Revert portions of that commit to bring DFS back, and add a new
combination to support 2-channels concurrency. This is valid because the
MAC80211 restrict works on each individual combination, but does not care
about them as a whole, as far as DFS is concerned.

This change applies to WCN7850 only, other chips are not affected.

Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.1.c5-00284.1-QCAHMTSWPL_V1.0_V2.0_SILICONZ-3

Fixes: 176f3009ae59 ("wifi: ath12k: support 2 channels for single pdev device")
Reported-by: Mihai Moldovan <ionic at ionic.de>
Closes: https://bugzilla.kernel.org/show_bug.cgi?id=220346 # 1
Signed-off-by: Baochen Qiang <baochen.qiang at oss.qualcomm.com>
---
 drivers/net/wireless/ath/ath12k/mac.c | 47 ++++++++++++++++++++++-------------
 1 file changed, 30 insertions(+), 17 deletions(-)

diff --git a/drivers/net/wireless/ath/ath12k/mac.c b/drivers/net/wireless/ath/ath12k/mac.c
index bf612079b8bdae18a043913dbfe1ff7cbd9eaa34..97d8b4e287fc361516e93c7d32436f07e4728896 100644
--- a/drivers/net/wireless/ath/ath12k/mac.c
+++ b/drivers/net/wireless/ath/ath12k/mac.c
@@ -13364,16 +13364,12 @@ ath12k_mac_setup_radio_iface_comb(struct ath12k *ar,
 	comb[0].beacon_int_infra_match = true;
 	comb[0].beacon_int_min_gcd = 100;
 
-	if (ar->ab->hw_params->single_pdev_only) {
-		comb[0].num_different_channels = 2;
-	} else {
-		comb[0].num_different_channels = 1;
-		comb[0].radar_detect_widths = BIT(NL80211_CHAN_WIDTH_20_NOHT) |
-						BIT(NL80211_CHAN_WIDTH_20) |
-						BIT(NL80211_CHAN_WIDTH_40) |
-						BIT(NL80211_CHAN_WIDTH_80) |
-						BIT(NL80211_CHAN_WIDTH_160);
-	}
+	comb[0].num_different_channels = 1;
+	comb[0].radar_detect_widths = BIT(NL80211_CHAN_WIDTH_20_NOHT) |
+				      BIT(NL80211_CHAN_WIDTH_20) |
+				      BIT(NL80211_CHAN_WIDTH_40) |
+				      BIT(NL80211_CHAN_WIDTH_80) |
+				      BIT(NL80211_CHAN_WIDTH_160);
 
 	return 0;
 }
@@ -13456,25 +13452,42 @@ static int ath12k_mac_setup_iface_combinations(struct ath12k_hw *ah)
 	struct ieee80211_iface_combination *combinations, *comb;
 	struct wiphy *wiphy = ah->hw->wiphy;
 	struct wiphy_radio *radio;
+	int n_combinations = 1;
 	struct ath12k *ar;
 	int i, ret;
 
-	combinations = kzalloc(sizeof(*combinations), GFP_KERNEL);
-	if (!combinations)
-		return -ENOMEM;
-
 	if (ah->num_radio == 1) {
-		ret = ath12k_mac_setup_radio_iface_comb(&ah->radio[0],
-							combinations);
+		ar = &ah->radio[0];
+
+		if (ar->ab->hw_params->single_pdev_only)
+			n_combinations = 2;
+
+		combinations = kcalloc(n_combinations, sizeof(*combinations),
+				       GFP_KERNEL);
+		if (!combinations)
+			return -ENOMEM;
+
+		ret = ath12k_mac_setup_radio_iface_comb(ar, combinations);
 		if (ret) {
 			ath12k_hw_warn(ah, "failed to setup radio interface combinations for one radio: %d",
 				       ret);
 			goto err_free_combinations;
 		}
 
+		if (ar->ab->hw_params->single_pdev_only) {
+			comb = combinations + 1;
+			memcpy(comb, combinations, sizeof(*comb));
+			comb->num_different_channels = 2;
+			comb->radar_detect_widths = 0;
+		}
+
 		goto out;
 	}
 
+	combinations = kcalloc(n_combinations, sizeof(*combinations), GFP_KERNEL);
+	if (!combinations)
+		return -ENOMEM;
+
 	/* there are multiple radios */
 
 	radio = kcalloc(ah->num_radio, sizeof(*radio), GFP_KERNEL);
@@ -13517,7 +13530,7 @@ static int ath12k_mac_setup_iface_combinations(struct ath12k_hw *ah)
 
 out:
 	wiphy->iface_combinations = combinations;
-	wiphy->n_iface_combinations = 1;
+	wiphy->n_iface_combinations = n_combinations;
 
 	return 0;
 

---
base-commit: 5a1ad8faaa165028dfcce650e20868c8fb7148cb
change-id: 20250718-ath12k-dfs-82472cfb996d

Best regards,
-- 
Baochen Qiang <baochen.qiang at oss.qualcomm.com>