wifi: ath12k: Avoid CPU busy-wait by handling VDEV_STAT and BCN_STAT

When the ath12k driver is built without CONFIG_ATH12K_DEBUG, the
recently refactored stats code can cause any user space application
(such at NetworkManager) to consume 100% CPU for 3 seconds, every time
stats are read.

Commit 'b8a0d83fe4c7 ("wifi: ath12k: move firmware stats out of
debugfs")' moved ath12k_debugfs_fw_stats_request() out of debugfs, by
merging the additional logic into ath12k_mac_get_fw_stats().

Among the added responsibility of ath12k_mac_get_fw_stats() was the
busy-wait for `fw_stats_done`.

Signalling of `fw_stats_done` happens when one of the
WMI_REQUEST_PDEV_STAT, WMI_REQUEST_VDEV_STAT, and WMI_REQUEST_BCN_STAT
messages are received, but the handling of the latter two commands remained
in the debugfs code. As `fw_stats_done` isn't signalled, the calling
processes will spin until the timeout (3 seconds) is reached.

Moving the handling of these two additional responses out of debugfs
resolves the issue.

Fixes: b8a0d83fe4c7 ("wifi: ath12k: move firmware stats out of debugfs")
Signed-off-by: Bjorn Andersson <bjorn.andersson@oss.qualcomm.com>
Tested-by: Abel Vesa <abel.vesa@linaro.org>
Link: https://patch.msgid.link/20250609-ath12k-fw-stats-done-v1-1-2b3624656697@oss.qualcomm.com
Signed-off-by: Jeff Johnson <jeff.johnson@oss.qualcomm.com>

diff --git a/drivers/net/wireless/ath/ath12k/debugfs.c b/drivers/net/wireless/ath/ath12k/debugfs.c
index dd624d73b8b2714e77c9d89b5a52f7b3fcb02951..23da93afaa5c25e806c9859dbbdd796afd23d78a 100644 (file)
--- a/drivers/net/wireless/ath/ath12k/debugfs.c
+++ b/drivers/net/wireless/ath/ath12k/debugfs.c
@@ -1251,64 +1251,6 @@ void ath12k_debugfs_soc_destroy(struct ath12k_base *ab)
         */
 }
 
-void
-ath12k_debugfs_fw_stats_process(struct ath12k *ar,
-                               struct ath12k_fw_stats *stats)
-{
-       struct ath12k_base *ab = ar->ab;
-       struct ath12k_pdev *pdev;
-       bool is_end;
-       static unsigned int num_vdev, num_bcn;
-       size_t total_vdevs_started = 0;
-       int i;
-
-       if (stats->stats_id == WMI_REQUEST_VDEV_STAT) {
-               if (list_empty(&stats->vdevs)) {
-                       ath12k_warn(ab, "empty vdev stats");
-                       return;
-               }
-               /* FW sends all the active VDEV stats irrespective of PDEV,
-                * hence limit until the count of all VDEVs started
-                */
-               rcu_read_lock();
-               for (i = 0; i < ab->num_radios; i++) {
-                       pdev = rcu_dereference(ab->pdevs_active[i]);
-                       if (pdev && pdev->ar)
-                               total_vdevs_started += pdev->ar->num_started_vdevs;
-               }
-               rcu_read_unlock();
-
-               is_end = ((++num_vdev) == total_vdevs_started);
-
-               list_splice_tail_init(&stats->vdevs,
-                                     &ar->fw_stats.vdevs);
-
-               if (is_end) {
-                       ar->fw_stats.fw_stats_done = true;
-                       num_vdev = 0;
-               }
-               return;
-       }
-       if (stats->stats_id == WMI_REQUEST_BCN_STAT) {
-               if (list_empty(&stats->bcn)) {
-                       ath12k_warn(ab, "empty beacon stats");
-                       return;
-               }
-               /* Mark end until we reached the count of all started VDEVs
-                * within the PDEV
-                */
-               is_end = ((++num_bcn) == ar->num_started_vdevs);
-
-               list_splice_tail_init(&stats->bcn,
-                                     &ar->fw_stats.bcn);
-
-               if (is_end) {
-                       ar->fw_stats.fw_stats_done = true;
-                       num_bcn = 0;
-               }
-       }
-}
-
 static int ath12k_open_vdev_stats(struct inode *inode, struct file *file)
 {
        struct ath12k *ar = inode->i_private;

diff --git a/drivers/net/wireless/ath/ath12k/debugfs.h b/drivers/net/wireless/ath/ath12k/debugfs.h
index ebef7dace3448e4bdf2d6cb155d089267315172c..21641a8a03460c6cc1b34929a353e5605bb834ce 100644 (file)
--- a/drivers/net/wireless/ath/ath12k/debugfs.h
+++ b/drivers/net/wireless/ath/ath12k/debugfs.h
@@ -12,8 +12,6 @@ void ath12k_debugfs_soc_create(struct ath12k_base *ab);
 void ath12k_debugfs_soc_destroy(struct ath12k_base *ab);
 void ath12k_debugfs_register(struct ath12k *ar);
 void ath12k_debugfs_unregister(struct ath12k *ar);
-void ath12k_debugfs_fw_stats_process(struct ath12k *ar,
-                                    struct ath12k_fw_stats *stats);
 void ath12k_debugfs_op_vif_add(struct ieee80211_hw *hw,
                               struct ieee80211_vif *vif);
 void ath12k_debugfs_pdev_create(struct ath12k_base *ab);
@@ -126,11 +124,6 @@ static inline void ath12k_debugfs_unregister(struct ath12k *ar)
 {
 }
 
-static inline void ath12k_debugfs_fw_stats_process(struct ath12k *ar,
-                                                  struct ath12k_fw_stats *stats)
-{
-}
-
 static inline bool ath12k_debugfs_is_extd_rx_stats_enabled(struct ath12k *ar)
 {
        return false;

diff --git a/drivers/net/wireless/ath/ath12k/wmi.c b/drivers/net/wireless/ath/ath12k/wmi.c
index 60e2444fe08cefa39ae218d07eb9736d2a0c982b..2d2444417e2b2d9281754d113f2b073034e27739 100644 (file)
--- a/drivers/net/wireless/ath/ath12k/wmi.c
+++ b/drivers/net/wireless/ath/ath12k/wmi.c
@@ -7626,6 +7626,63 @@ static int ath12k_wmi_pull_fw_stats(struct ath12k_base *ab, struct sk_buff *skb,
                                   &parse);
 }
 
+static void ath12k_wmi_fw_stats_process(struct ath12k *ar,
+                                       struct ath12k_fw_stats *stats)
+{
+       struct ath12k_base *ab = ar->ab;
+       struct ath12k_pdev *pdev;
+       bool is_end;
+       static unsigned int num_vdev, num_bcn;
+       size_t total_vdevs_started = 0;
+       int i;
+
+       if (stats->stats_id == WMI_REQUEST_VDEV_STAT) {
+               if (list_empty(&stats->vdevs)) {
+                       ath12k_warn(ab, "empty vdev stats");
+                       return;
+               }
+               /* FW sends all the active VDEV stats irrespective of PDEV,
+                * hence limit until the count of all VDEVs started
+                */
+               rcu_read_lock();
+               for (i = 0; i < ab->num_radios; i++) {
+                       pdev = rcu_dereference(ab->pdevs_active[i]);
+                       if (pdev && pdev->ar)
+                               total_vdevs_started += pdev->ar->num_started_vdevs;
+               }
+               rcu_read_unlock();
+
+               is_end = ((++num_vdev) == total_vdevs_started);
+
+               list_splice_tail_init(&stats->vdevs,
+                                     &ar->fw_stats.vdevs);
+
+               if (is_end) {
+                       ar->fw_stats.fw_stats_done = true;
+                       num_vdev = 0;
+               }
+               return;
+       }
+       if (stats->stats_id == WMI_REQUEST_BCN_STAT) {
+               if (list_empty(&stats->bcn)) {
+                       ath12k_warn(ab, "empty beacon stats");
+                       return;
+               }
+               /* Mark end until we reached the count of all started VDEVs
+                * within the PDEV
+                */
+               is_end = ((++num_bcn) == ar->num_started_vdevs);
+
+               list_splice_tail_init(&stats->bcn,
+                                     &ar->fw_stats.bcn);
+
+               if (is_end) {
+                       ar->fw_stats.fw_stats_done = true;
+                       num_bcn = 0;
+               }
+       }
+}
+
 static void ath12k_update_stats_event(struct ath12k_base *ab, struct sk_buff *skb)
 {
        struct ath12k_fw_stats stats = {};
@@ -7655,19 +7712,15 @@ static void ath12k_update_stats_event(struct ath12k_base *ab, struct sk_buff *sk
 
        spin_lock_bh(&ar->data_lock);
 
-       /* WMI_REQUEST_PDEV_STAT can be requested via .get_txpower mac ops or via
-        * debugfs fw stats. Therefore, processing it separately.
-        */
+       /* Handle WMI_REQUEST_PDEV_STAT status update */
        if (stats.stats_id == WMI_REQUEST_PDEV_STAT) {
                list_splice_tail_init(&stats.pdevs, &ar->fw_stats.pdevs);
                ar->fw_stats.fw_stats_done = true;
                goto complete;
        }
 
-       /* WMI_REQUEST_VDEV_STAT and WMI_REQUEST_BCN_STAT are currently requested only
-        * via debugfs fw stats. Hence, processing these in debugfs context.
-        */
-       ath12k_debugfs_fw_stats_process(ar, &stats);
+       /* Handle WMI_REQUEST_VDEV_STAT and WMI_REQUEST_BCN_STAT updates. */
+       ath12k_wmi_fw_stats_process(ar, &stats);
 
 complete:
        complete(&ar->fw_stats_complete);