6.1-stable review patch. If anyone has any objections, please let me know.
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From: Baochen Qiang quic_bqiang@quicinc.com
[ Upstream commit 9f6e82d11bb9692a90d20b10f87345598945c803 ]
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@unformed.ru Closes: https://lore.kernel.org/all/7324ac7a-8b7a-42a5-aa19-de52138ff638@app.fastmai... # [1] Signed-off-by: Baochen Qiang quic_bqiang@quicinc.com Reviewed-by: Vasanthakumar Thiagarajan vasanthakumar.thiagarajan@oss.qualcomm.com Link: https://patch.msgid.link/20250220082448.31039-2-quic_bqiang@quicinc.com Signed-off-by: Jeff Johnson jeff.johnson@oss.qualcomm.com Signed-off-by: Sasha Levin sashal@kernel.org --- 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 ef269244fe495..a8bdddccca4cb 100644 --- a/drivers/net/wireless/ath/ath11k/core.c +++ b/drivers/net/wireless/ath/ath11k/core.c @@ -644,6 +644,7 @@ 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 bd06536f82a64..69feef410b359 100644 --- a/drivers/net/wireless/ath/ath11k/core.h +++ b/drivers/net/wireless/ath/ath11k/core.h @@ -718,7 +718,7 @@ 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 a8bd944f76d92..a5791155fe065 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 8234e34269ed8..e5b4cc2486833 100644 --- a/drivers/net/wireless/ath/ath11k/mac.c +++ b/drivers/net/wireless/ath/ath11k/mac.c @@ -8510,11 +8510,11 @@ 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 142b201052660..38756ed48082c 100644 --- a/drivers/net/wireless/ath/ath11k/wmi.c +++ b/drivers/net/wireless/ath/ath11k/wmi.c @@ -7575,7 +7575,7 @@ 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; }