[PATCH v7 6/6] wifi: mt76: mt7925: fix MLO ROC setup error handling

[Zac]

Replace noisy WARN_ON_ONCE checks with silent returns in
mt7925_mcu_set_mlo_roc(). During MLO setup, links may not be fully
configured when ROC is requested. The WARN_ON_ONCE statements were
triggering unnecessary kernel warnings during normal operation.

Changes:
- Replace WARN_ON_ONCE(!link_conf) with silent if (!link_conf)
- Replace WARN_ON_ONCE(!links[i].chan) with silent check
- Add explicit mconf NULL check before use
- Use -ENOLINK error code to indicate link not ready
- Replace continue with return to fail fast on invalid links

The -ENOLINK error code properly indicates that the link is not yet
ready for ROC, allowing upper layers to retry later without generating
spurious kernel warnings.

Fixes: c948b5da6bbe ("wifi: mt76: mt7925: add Mediatek Wi-Fi7 driver for mt7925 device")
Signed-off-by: Zac Bowling <zac at zacbowling.com>
---
 .../net/wireless/mediatek/mt76/mt7925/mcu.c   | 20 +++++++++++++------
 1 file changed, 14 insertions(+), 6 deletions(-)

diff --git a/drivers/net/wireless/mediatek/mt76/mt7925/mcu.c b/drivers/net/wireless/mediatek/mt76/mt7925/mcu.c
index 2ed4af282120..5ca2106b1ce0 100644
--- a/drivers/net/wireless/mediatek/mt76/mt7925/mcu.c
+++ b/drivers/net/wireless/mediatek/mt76/mt7925/mcu.c
@@ -1341,15 +1341,23 @@ int mt7925_mcu_set_mlo_roc(struct mt792x_phy *phy, struct mt792x_bss_conf *mconf
 	for (i = 0; i < ARRAY_SIZE(links); i++) {
 		links[i].id = i ? __ffs(~BIT(mconf->link_id) & sel_links) :
 				 mconf->link_id;
+
 		link_conf = mt792x_vif_to_bss_conf(vif, links[i].id);
-		if (WARN_ON_ONCE(!link_conf))
-			return -EPERM;
+		if (!link_conf)
+			return -ENOLINK;
 
 		links[i].chan = link_conf->chanreq.oper.chan;
-		if (WARN_ON_ONCE(!links[i].chan))
-			return -EPERM;
+		if (!links[i].chan)
+			/* Channel not configured yet - this can happen during
+			 * MLO AP setup when links are being added sequentially.
+			 * Return -ENOLINK to indicate link not ready.
+			 */
+			return -ENOLINK;
 
 		links[i].mconf = mt792x_vif_to_link(mvif, links[i].id);
+		if (!links[i].mconf)
+			return -ENOLINK;
+
 		links[i].tag = links[i].id == mconf->link_id ?
 			       UNI_ROC_ACQUIRE : UNI_ROC_SUB_LINK;
 
@@ -1364,8 +1372,8 @@ int mt7925_mcu_set_mlo_roc(struct mt792x_phy *phy, struct mt792x_bss_conf *mconf
 		type = MT7925_ROC_REQ_JOIN;
 
 	for (i = 0; i < ARRAY_SIZE(links) && i < hweight16(vif->active_links); i++) {
-		if (WARN_ON_ONCE(!links[i].mconf || !links[i].chan))
-			continue;
+		if (!links[i].mconf || !links[i].chan)
+			return -ENOLINK;
 
 		chan = links[i].chan;
 		center_ch = ieee80211_frequency_to_channel(chan->center_freq);
-- 
2.52.0