We get report [1] that CPU is running a hot loop in
ath11k_debugfs_fw_stats_request():
94.60% 0.00% i3status [kernel.kallsyms] [k] do_syscall_64
|
--94.60%--do_syscall_64
|
--94.55%--__sys_sendmsg
___sys_sendmsg
____sys_sendmsg
netlink_sendmsg
netlink_unicast
genl_rcv
netlink_rcv_skb
genl_rcv_msg
|
--94.55%--genl_family_rcv_msg_dumpit
__netlink_dump_start
netlink_dump
genl_dumpit
nl80211_dump_station
|
--94.55%--ieee80211_dump_station
sta_set_sinfo
|
--94.55%--ath11k_mac_op_sta_statistics
ath11k_debugfs_get_fw_stats
|
--94.55%--ath11k_debugfs_fw_stats_request
|
|--41.73%--_raw_spin_lock_bh
|
|--22.74%--__local_bh_enable_ip
|
|--9.22%--_raw_spin_unlock_bh
|
--6.66%--srso_alias_safe_ret
This is because, if for whatever reason ar->fw_stats_done is not set by
ath11k_update_stats_event(), ath11k_debugfs_fw_stats_request() won't yield
CPU before an up to 3s timeout.
Change to completion mechanism to avoid CPU burning.
Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-03125-QCAHSPSWPL_V1_V2_SILICONZ_LITE-3.6510.37
Fixes: d5c65159f289 ("ath11k: driver for Qualcomm IEEE 802.11ax devices")
Reported-by: Yury Vostrikov <mon@xxxxxxxxxxx>
Closes: https://lore.kernel.org/all/7324ac7a-8b7a-42a5-aa19-de52138ff638@xxxxxxxxxxxxxxxx/ # [1]
Signed-off-by: Baochen Qiang <quic_bqiang@xxxxxxxxxxx>
---
drivers/net/wireless/ath/ath11k/core.c | 1 +
drivers/net/wireless/ath/ath11k/core.h | 2 +-
drivers/net/wireless/ath/ath11k/debugfs.c | 38 +++++++++--------------
drivers/net/wireless/ath/ath11k/mac.c | 2 +-
drivers/net/wireless/ath/ath11k/wmi.c | 2 +-
5 files changed, 18 insertions(+), 27 deletions(-)
diff --git a/drivers/net/wireless/ath/ath11k/core.c b/drivers/net/wireless/ath/ath11k/core.c
index 65bba0ae69a9..251c20148ab2 100644
--- a/drivers/net/wireless/ath/ath11k/core.c
+++ b/drivers/net/wireless/ath/ath11k/core.c
@@ -951,6 +951,7 @@ void ath11k_fw_stats_init(struct ath11k *ar)
INIT_LIST_HEAD(&ar->fw_stats.bcn);
init_completion(&ar->fw_stats_complete);
+ init_completion(&ar->fw_stats_done);
}
void ath11k_fw_stats_free(struct ath11k_fw_stats *stats)
diff --git a/drivers/net/wireless/ath/ath11k/core.h b/drivers/net/wireless/ath/ath11k/core.h
index 1a3d0de4afde..6abbb29034f0 100644
--- a/drivers/net/wireless/ath/ath11k/core.h
+++ b/drivers/net/wireless/ath/ath11k/core.h
@@ -783,7 +783,7 @@ struct ath11k {
u8 alpha2[REG_ALPHA2_LEN + 1];
struct ath11k_fw_stats fw_stats;
struct completion fw_stats_complete;
- bool fw_stats_done;
+ struct completion fw_stats_done;
/* protected by conf_mutex */
bool ps_state_enable;
diff --git a/drivers/net/wireless/ath/ath11k/debugfs.c b/drivers/net/wireless/ath/ath11k/debugfs.c
index bf192529e3fe..1d03e3aab011 100644
--- a/drivers/net/wireless/ath/ath11k/debugfs.c
+++ b/drivers/net/wireless/ath/ath11k/debugfs.c
@@ -1,7 +1,7 @@
// SPDX-License-Identifier: BSD-3-Clause-Clear
/*
* Copyright (c) 2018-2020 The Linux Foundation. All rights reserved.
- * Copyright (c) 2021-2024 Qualcomm Innovation Center, Inc. All rights reserved.
+ * Copyright (c) 2021-2025 Qualcomm Innovation Center, Inc. All rights reserved.
*/
#include <linux/vmalloc.h>
@@ -96,7 +96,6 @@ void ath11k_debugfs_add_dbring_entry(struct ath11k *ar,
static void ath11k_debugfs_fw_stats_reset(struct ath11k *ar)
{
spin_lock_bh(&ar->data_lock);
- ar->fw_stats_done = false;
ath11k_fw_stats_pdevs_free(&ar->fw_stats.pdevs);
ath11k_fw_stats_vdevs_free(&ar->fw_stats.vdevs);
spin_unlock_bh(&ar->data_lock);
@@ -114,7 +113,7 @@ void ath11k_debugfs_fw_stats_process(struct ath11k *ar, struct ath11k_fw_stats *
/* WMI_REQUEST_PDEV_STAT request has been already processed */
if (stats->stats_id == WMI_REQUEST_RSSI_PER_CHAIN_STAT) {
- ar->fw_stats_done = true;
+ complete(&ar->fw_stats_done);
return;
}
@@ -138,7 +137,7 @@ void ath11k_debugfs_fw_stats_process(struct ath11k *ar, struct ath11k_fw_stats *
&ar->fw_stats.vdevs);
if (is_end) {
- ar->fw_stats_done = true;
+ complete(&ar->fw_stats_done);
num_vdev = 0;
}
return;
@@ -158,7 +157,7 @@ void ath11k_debugfs_fw_stats_process(struct ath11k *ar, struct ath11k_fw_stats *
&ar->fw_stats.bcn);
if (is_end) {
- ar->fw_stats_done = true;
+ complete(&ar->fw_stats_done);
num_bcn = 0;
}
}
@@ -168,21 +167,15 @@ static int ath11k_debugfs_fw_stats_request(struct ath11k *ar,
struct stats_request_params *req_param)
{
struct ath11k_base *ab = ar->ab;
- unsigned long timeout, time_left;
+ unsigned long time_left;
int ret;
lockdep_assert_held(&ar->conf_mutex);
- /* FW stats can get split when exceeding the stats data buffer limit.
- * In that case, since there is no end marking for the back-to-back
- * received 'update stats' event, we keep a 3 seconds timeout in case,
- * fw_stats_done is not marked yet
- */
- timeout = jiffies + secs_to_jiffies(3);
-
ath11k_debugfs_fw_stats_reset(ar);
reinit_completion(&ar->fw_stats_complete);
+ reinit_completion(&ar->fw_stats_done);
ret = ath11k_wmi_send_stats_request_cmd(ar, req_param);
@@ -193,21 +186,18 @@ static int ath11k_debugfs_fw_stats_request(struct ath11k *ar,
}
time_left = wait_for_completion_timeout(&ar->fw_stats_complete, 1 * HZ);
-
if (!time_left)
return -ETIMEDOUT;
- for (;;) {
- if (time_after(jiffies, timeout))
- break;
+ /* FW stats can get split when exceeding the stats data buffer limit.
+ * In that case, since there is no end marking for the back-to-back
+ * received 'update stats' event, we keep a 3 seconds timeout in case,
+ * fw_stats_done is not marked yet
+ */
+ time_left = wait_for_completion_timeout(&ar->fw_stats_done, 3 * HZ);
+ if (!time_left)
+ return -ETIMEDOUT;
- spin_lock_bh(&ar->data_lock);
- if (ar->fw_stats_done) {
- spin_unlock_bh(&ar->data_lock);
- break;
- }
- spin_unlock_bh(&ar->data_lock);
- }
return 0;
}
diff --git a/drivers/net/wireless/ath/ath11k/mac.c b/drivers/net/wireless/ath/ath11k/mac.c
index 14ed53836589..d35250f4570d 100644
--- a/drivers/net/wireless/ath/ath11k/mac.c
+++ b/drivers/net/wireless/ath/ath11k/mac.c
@@ -9385,11 +9385,11 @@ static int ath11k_fw_stats_request(struct ath11k *ar,
lockdep_assert_held(&ar->conf_mutex);
spin_lock_bh(&ar->data_lock);
- ar->fw_stats_done = false;
ath11k_fw_stats_pdevs_free(&ar->fw_stats.pdevs);
spin_unlock_bh(&ar->data_lock);
reinit_completion(&ar->fw_stats_complete);
+ reinit_completion(&ar->fw_stats_done);
ret = ath11k_wmi_send_stats_request_cmd(ar, req_param);
if (ret) {
diff --git a/drivers/net/wireless/ath/ath11k/wmi.c b/drivers/net/wireless/ath/ath11k/wmi.c
index d7f852bebf4a..27cb0bb06b93 100644
--- a/drivers/net/wireless/ath/ath11k/wmi.c
+++ b/drivers/net/wireless/ath/ath11k/wmi.c
@@ -8189,7 +8189,7 @@ static void ath11k_update_stats_event(struct ath11k_base *ab, struct sk_buff *sk
*/
if (stats.stats_id == WMI_REQUEST_PDEV_STAT) {
list_splice_tail_init(&stats.pdevs, &ar->fw_stats.pdevs);
- ar->fw_stats_done = true;
+ complete(&ar->fw_stats_done);
goto complete;
}
--
2.25.1
