wifi: ath12k: Prepare ahvif scan link for parallel scan

When two split-phy devices that support overlapping frequency ranges within
the same band(say 5 GHz low and 5 GHz high) are grouped into an ath12k
hardware (HW) setup, they share a common wiphy instance. Consequently, the
channel list (wiphy->bands[]) becomes unified across all associated
radios (ar).

When a scan is triggered with frequency list containing frequencies of
both 5 GHz low and 5 GHz high, mac80211 generates a single scan request
to driver with all the frequencies. This is because mac80211 splits the
scan request based on band.

ath12k checks the first frequency in the requested scan frequency list and
initiates scan to corresponding radio's(ar) firmware with all the
frequencies. Firmware rejects this scan since some of the frequencies in
the scan request are not supported, resulting in a scan failure.
To fix this ath12k driver should split the scan request into multiple
scans based on requested frequencies and schedule them to corresponding
underlying radio(s) in parallel.

Currently, ath12k driver assigns the scan link (link 15) in ahvif->links[]
for scan vdev creation. However, with parallel scan support being
introduced in the following patch, multiple radios (e.g., 5 GHz low and
5 GHz high) in the same HW group may attempt to use the same scan link
concurrently, causing conflicts where the vdev created by one radio could
be deleted and re-initialized by another.

To address this, reserve space for additional scan links for each radio in
a MLO group and allow subsequent radios to use different available scan
links (ahvif->link[15..MAX_SCAN_LINKS]) when scan link (15) is
pre-occupied.
While at it, rename ATH12K_DEFAULT_SCAN_LINK as ATH12K_FIRST_SCAN_LINK
as there is no longer only one scan link.

Tested-on: QCN9274 hw2.0 PCI WLAN.WBE.1.4.1-00199-QCAHKSWPL_SILICONZ-1

Signed-off-by: Rameshkumar Sundaram <rameshkumar.sundaram@oss.qualcomm.com>
Reviewed-by: Mahendran P <quic_mahep@quicinc.com>
Link: https://patch.msgid.link/20250507194832.2501668-2-rameshkumar.sundaram@oss.qualcomm.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>

diff --git a/drivers/net/wireless/ath/ath12k/core.h b/drivers/net/wireless/ath/ath12k/core.h
index 7bcd9c70309fdb733830a19323012a389d17fd9c..9021e44e17e5a2b870f06ec421aa71276d731983 100644 (file)
--- a/drivers/net/wireless/ath/ath12k/core.h
+++ b/drivers/net/wireless/ath/ath12k/core.h
@@ -380,7 +380,7 @@ struct ath12k_vif {
        struct ath12k_link_vif __rcu *link[ATH12K_NUM_MAX_LINKS];
        struct ath12k_vif_cache *cache[IEEE80211_MLD_MAX_NUM_LINKS];
        /* indicates bitmap of link vif created in FW */
-       u16 links_map;
+       u32 links_map;
        u8 last_scan_link;
 
        /* Must be last - ends in a flexible-array member.

diff --git a/drivers/net/wireless/ath/ath12k/mac.c b/drivers/net/wireless/ath/ath12k/mac.c
index 1077b19a89c9cbaca8ea3c7152dfe630342d2aff..d6bd54e48521c8de33daeeb3c72854d2327884ad 100644 (file)
--- a/drivers/net/wireless/ath/ath12k/mac.c
+++ b/drivers/net/wireless/ath/ath12k/mac.c
@@ -3499,7 +3499,7 @@ static struct ath12k_link_vif *ath12k_mac_assign_link_vif(struct ath12k_hw *ah,
        /* If this is the first link arvif being created for an ML VIF
         * use the preallocated deflink memory except for scan arvifs
         */
-       if (!ahvif->links_map && link_id != ATH12K_DEFAULT_SCAN_LINK) {
+       if (!ahvif->links_map && link_id < ATH12K_FIRST_SCAN_LINK) {
                arvif = &ahvif->deflink;
 
                if (vif->type == NL80211_IFTYPE_STATION)
@@ -4491,11 +4491,12 @@ ath12k_mac_find_link_id_by_ar(struct ath12k_vif *ahvif, struct ath12k *ar)
        struct ath12k_link_vif *arvif;
        struct ath12k_hw *ah = ahvif->ah;
        unsigned long links = ahvif->links_map;
+       unsigned long scan_links_map;
        u8 link_id;
 
        lockdep_assert_wiphy(ah->hw->wiphy);
 
-       for_each_set_bit(link_id, &links, IEEE80211_MLD_MAX_NUM_LINKS) {
+       for_each_set_bit(link_id, &links, ATH12K_NUM_MAX_LINKS) {
                arvif = wiphy_dereference(ah->hw->wiphy, ahvif->link[link_id]);
 
                if (!arvif || !arvif->is_created)
@@ -4505,10 +4506,20 @@ ath12k_mac_find_link_id_by_ar(struct ath12k_vif *ahvif, struct ath12k *ar)
                        return link_id;
        }
 
-       /* input ar is not assigned to any of the links of ML VIF, use scan
-        * link (15) for scan vdev creation.
+       /* input ar is not assigned to any of the links of ML VIF, use next
+        * available scan link for scan vdev creation. There are cases where
+        * single scan req needs to be split in driver and initiate separate
+        * scan requests to firmware based on device.
         */
-       return ATH12K_DEFAULT_SCAN_LINK;
+
+        /* Unset all non-scan links (0-14) of scan_links_map so that ffs() will
+         * choose an available link among scan links (i.e link id >= 15)
+         */
+       scan_links_map = ~ahvif->links_map & ATH12K_SCAN_LINKS_MASK;
+       if (scan_links_map)
+               return __ffs(scan_links_map);
+
+       return ATH12K_FIRST_SCAN_LINK;
 }
 
 static int ath12k_mac_op_hw_scan(struct ieee80211_hw *hw,
@@ -4539,9 +4550,16 @@ static int ath12k_mac_op_hw_scan(struct ieee80211_hw *hw,
 
        /* check if any of the links of ML VIF is already started on
         * radio(ar) corresponding to given scan frequency and use it,
-        * if not use scan link (link 15) for scan purpose.
+        * if not use scan link (link id >= 15) for scan purpose.
         */
        link_id = ath12k_mac_find_link_id_by_ar(ahvif, ar);
+       /* All scan links are occupied. ideally this shouldn't happen as
+        * mac80211 won't schedule scan for same band until ongoing scan is
+        * completed, don't try to exceed max links just in case if it happens.
+        */
+       if (link_id >= ATH12K_NUM_MAX_LINKS)
+               return -EBUSY;
+
        arvif = ath12k_mac_assign_link_vif(ah, vif, link_id);
 
        ath12k_dbg(ar->ab, ATH12K_DBG_MAC, "mac link ID %d selected for scan",
@@ -9068,7 +9086,8 @@ static struct ath12k *ath12k_mac_assign_vif_to_vdev(struct ieee80211_hw *hw,
        struct ath12k_hw *ah = hw->priv;
        struct ath12k *ar;
        struct ath12k_base *ab;
-       u8 link_id = arvif->link_id;
+       u8 link_id = arvif->link_id, scan_link_id;
+       unsigned long scan_link_map;
        int ret;
 
        lockdep_assert_wiphy(hw->wiphy);
@@ -9087,12 +9106,16 @@ static struct ath12k *ath12k_mac_assign_vif_to_vdev(struct ieee80211_hw *hw,
         * and now we want to create for actual usage.
         */
        if (ieee80211_vif_is_mld(vif)) {
-               scan_arvif = wiphy_dereference(hw->wiphy,
-                                              ahvif->link[ATH12K_DEFAULT_SCAN_LINK]);
-               if (scan_arvif && scan_arvif->ar == ar) {
-                       ar->scan.arvif = NULL;
-                       ath12k_mac_remove_link_interface(hw, scan_arvif);
-                       ath12k_mac_unassign_link_vif(scan_arvif);
+               scan_link_map = ahvif->links_map & ATH12K_SCAN_LINKS_MASK;
+               for_each_set_bit(scan_link_id, &scan_link_map, ATH12K_NUM_MAX_LINKS) {
+                       scan_arvif = wiphy_dereference(hw->wiphy,
+                                                      ahvif->link[scan_link_id]);
+                       if (scan_arvif && scan_arvif->ar == ar) {
+                               ar->scan.arvif = NULL;
+                               ath12k_mac_remove_link_interface(hw, scan_arvif);
+                               ath12k_mac_unassign_link_vif(scan_arvif);
+                               break;
+                       }
                }
        }
 

diff --git a/drivers/net/wireless/ath/ath12k/mac.h b/drivers/net/wireless/ath/ath12k/mac.h
index cc81b1f5680f41c2ed59220e396e9e6b1c38d2c4..473611bfccdc3861864f29702304daa12ebf888d 100644 (file)
--- a/drivers/net/wireless/ath/ath12k/mac.h
+++ b/drivers/net/wireless/ath/ath12k/mac.h
@@ -51,8 +51,11 @@ struct ath12k_generic_iter {
 /* Default link after the IEEE802.11 defined Max link id limit
  * for driver usage purpose.
  */
-#define ATH12K_DEFAULT_SCAN_LINK       IEEE80211_MLD_MAX_NUM_LINKS
-#define ATH12K_NUM_MAX_LINKS           (IEEE80211_MLD_MAX_NUM_LINKS + 1)
+#define ATH12K_FIRST_SCAN_LINK IEEE80211_MLD_MAX_NUM_LINKS
+#define ATH12K_SCAN_MAX_LINKS  ATH12K_GROUP_MAX_RADIO
+/* Define 1 scan link for each radio for parallel scan purposes */
+#define ATH12K_NUM_MAX_LINKS (IEEE80211_MLD_MAX_NUM_LINKS + ATH12K_SCAN_MAX_LINKS)
+#define ATH12K_SCAN_LINKS_MASK GENMASK(ATH12K_NUM_MAX_LINKS, IEEE80211_MLD_MAX_NUM_LINKS)
 
 #define ATH12K_NUM_MAX_ACTIVE_LINKS_PER_DEVICE 2