The ieee80211_ops::sta_rc_update must be atomic, because
ieee80211_chan_bw_change() holds rcu_read lock while calling
drv_sta_rc_update(), so create a work to do original things.
Voluntary context switch within RCU read-side critical section!
WARNING: CPU: 0 PID: 4621 at kernel/rcu/tree_plugin.h:318
rcu_note_context_switch+0x571/0x5d0
CPU: 0 PID: 4621 Comm: kworker/u16:2 Tainted: G W OE
Workqueue: phy3 ieee80211_chswitch_work [mac80211]
RIP: 0010:rcu_note_context_switch+0x571/0x5d0
Call Trace:
<TASK>
__schedule+0xb0/0x1460
? __mod_timer+0x116/0x360
schedule+0x5a/0xc0
schedule_timeout+0x87/0x150
? trace_raw_output_tick_stop+0x60/0x60
wait_for_completion_timeout+0x7b/0x140
usb_start_wait_urb+0x82/0x160 [usbcore
usb_control_msg+0xe3/0x140 [usbcore
rtw_usb_read+0x88/0xe0 [rtw_usb
rtw_usb_read8+0xf/0x10 [rtw_usb
rtw_fw_send_h2c_command+0xa0/0x170 [rtw_core
rtw_fw_send_ra_info+0xc9/0xf0 [rtw_core
drv_sta_rc_update+0x7c/0x160 [mac80211
ieee80211_chan_bw_change+0xfb/0x110 [mac80211
ieee80211_change_chanctx+0x38/0x130 [mac80211
ieee80211_vif_use_reserved_switch+0x34e/0x900 [mac80211
ieee80211_link_use_reserved_context+0x88/0xe0 [mac80211
ieee80211_chswitch_work+0x95/0x170 [mac80211
process_one_work+0x201/0x410
worker_thread+0x4a/0x3b0
? process_one_work+0x410/0x410
kthread+0xe1/0x110
? kthread_complete_and_exit+0x20/0x20
ret_from_fork+0x1f/0x30
</TASK>
Cc: [email protected]
Fixes: c1edc86472fc ("rtw88: add ieee80211:sta_rc_update ops")
Reported-by: Larry Finger <[email protected]>
Link: https://lore.kernel.org/linux-wireless/[email protected]/T/#t
Signed-off-by: Ping-Ke Shih <[email protected]>
---
drivers/net/wireless/realtek/rtw88/mac80211.c | 2 +-
drivers/net/wireless/realtek/rtw88/main.c | 15 +++++++++++++++
drivers/net/wireless/realtek/rtw88/main.h | 3 +++
3 files changed, 19 insertions(+), 1 deletion(-)
diff --git a/drivers/net/wireless/realtek/rtw88/mac80211.c b/drivers/net/wireless/realtek/rtw88/mac80211.c
index 7aa6edad0d012..a6c024cab7ee4 100644
--- a/drivers/net/wireless/realtek/rtw88/mac80211.c
+++ b/drivers/net/wireless/realtek/rtw88/mac80211.c
@@ -918,7 +918,7 @@ static void rtw_ops_sta_rc_update(struct ieee80211_hw *hw,
struct rtw_sta_info *si = (struct rtw_sta_info *)sta->drv_priv;
if (changed & IEEE80211_RC_BW_CHANGED)
- rtw_update_sta_info(rtwdev, si, true);
+ ieee80211_queue_work(rtwdev->hw, &si->rc_work);
}
const struct ieee80211_ops rtw_ops = {
diff --git a/drivers/net/wireless/realtek/rtw88/main.c b/drivers/net/wireless/realtek/rtw88/main.c
index 5bf6b45815578..d30a191c9291d 100644
--- a/drivers/net/wireless/realtek/rtw88/main.c
+++ b/drivers/net/wireless/realtek/rtw88/main.c
@@ -319,6 +319,17 @@ static u8 rtw_acquire_macid(struct rtw_dev *rtwdev)
return mac_id;
}
+static void rtw_sta_rc_work(struct work_struct *work)
+{
+ struct rtw_sta_info *si = container_of(work, struct rtw_sta_info,
+ rc_work);
+ struct rtw_dev *rtwdev = si->rtwdev;
+
+ mutex_lock(&rtwdev->mutex);
+ rtw_update_sta_info(rtwdev, si, true);
+ mutex_unlock(&rtwdev->mutex);
+}
+
int rtw_sta_add(struct rtw_dev *rtwdev, struct ieee80211_sta *sta,
struct ieee80211_vif *vif)
{
@@ -329,12 +340,14 @@ int rtw_sta_add(struct rtw_dev *rtwdev, struct ieee80211_sta *sta,
if (si->mac_id >= RTW_MAX_MAC_ID_NUM)
return -ENOSPC;
+ si->rtwdev = rtwdev;
si->sta = sta;
si->vif = vif;
si->init_ra_lv = 1;
ewma_rssi_init(&si->avg_rssi);
for (i = 0; i < ARRAY_SIZE(sta->txq); i++)
rtw_txq_init(rtwdev, sta->txq[i]);
+ INIT_WORK(&si->rc_work, rtw_sta_rc_work);
rtw_update_sta_info(rtwdev, si, true);
rtw_fw_media_status_report(rtwdev, si->mac_id, true);
@@ -353,6 +366,8 @@ void rtw_sta_remove(struct rtw_dev *rtwdev, struct ieee80211_sta *sta,
struct rtw_sta_info *si = (struct rtw_sta_info *)sta->drv_priv;
int i;
+ cancel_work_sync(&si->rc_work);
+
rtw_release_macid(rtwdev, si->mac_id);
if (fw_exist)
rtw_fw_media_status_report(rtwdev, si->mac_id, false);
diff --git a/drivers/net/wireless/realtek/rtw88/main.h b/drivers/net/wireless/realtek/rtw88/main.h
index a563285e90ede..9e841f6991a9a 100644
--- a/drivers/net/wireless/realtek/rtw88/main.h
+++ b/drivers/net/wireless/realtek/rtw88/main.h
@@ -743,6 +743,7 @@ struct rtw_txq {
DECLARE_EWMA(rssi, 10, 16);
struct rtw_sta_info {
+ struct rtw_dev *rtwdev;
struct ieee80211_sta *sta;
struct ieee80211_vif *vif;
@@ -767,6 +768,8 @@ struct rtw_sta_info {
bool use_cfg_mask;
struct cfg80211_bitrate_mask *mask;
+
+ struct work_struct rc_work;
};
enum rtw_bfee_role {
--
2.25.1
On 5/8/23 03:54, Ping-Ke Shih wrote:
> The ieee80211_ops::sta_rc_update must be atomic, because
> ieee80211_chan_bw_change() holds rcu_read lock while calling
> drv_sta_rc_update(), so create a work to do original things.
>
> Voluntary context switch within RCU read-side critical section!
> WARNING: CPU: 0 PID: 4621 at kernel/rcu/tree_plugin.h:318
> rcu_note_context_switch+0x571/0x5d0
> CPU: 0 PID: 4621 Comm: kworker/u16:2 Tainted: G W OE
> Workqueue: phy3 ieee80211_chswitch_work [mac80211]
> RIP: 0010:rcu_note_context_switch+0x571/0x5d0
> Call Trace:
> <TASK>
> __schedule+0xb0/0x1460
> ? __mod_timer+0x116/0x360
> schedule+0x5a/0xc0
> schedule_timeout+0x87/0x150
> ? trace_raw_output_tick_stop+0x60/0x60
> wait_for_completion_timeout+0x7b/0x140
> usb_start_wait_urb+0x82/0x160 [usbcore
> usb_control_msg+0xe3/0x140 [usbcore
> rtw_usb_read+0x88/0xe0 [rtw_usb
> rtw_usb_read8+0xf/0x10 [rtw_usb
> rtw_fw_send_h2c_command+0xa0/0x170 [rtw_core
> rtw_fw_send_ra_info+0xc9/0xf0 [rtw_core
> drv_sta_rc_update+0x7c/0x160 [mac80211
> ieee80211_chan_bw_change+0xfb/0x110 [mac80211
> ieee80211_change_chanctx+0x38/0x130 [mac80211
> ieee80211_vif_use_reserved_switch+0x34e/0x900 [mac80211
> ieee80211_link_use_reserved_context+0x88/0xe0 [mac80211
> ieee80211_chswitch_work+0x95/0x170 [mac80211
> process_one_work+0x201/0x410
> worker_thread+0x4a/0x3b0
> ? process_one_work+0x410/0x410
> kthread+0xe1/0x110
> ? kthread_complete_and_exit+0x20/0x20
> ret_from_fork+0x1f/0x30
> </TASK>
>
> Cc: [email protected]
> Fixes: c1edc86472fc ("rtw88: add ieee80211:sta_rc_update ops")
> Reported-by: Larry Finger <[email protected]>
> Link: https://lore.kernel.org/linux-wireless/[email protected]/T/#t
> Signed-off-by: Ping-Ke Shih <[email protected]>
> ---
> drivers/net/wireless/realtek/rtw88/mac80211.c | 2 +-
> drivers/net/wireless/realtek/rtw88/main.c | 15 +++++++++++++++
> drivers/net/wireless/realtek/rtw88/main.h | 3 +++
> 3 files changed, 19 insertions(+), 1 deletion(-)
Tested-by: Larry Finger <[email protected]>
Thanks,
Larry
Ping-Ke Shih <[email protected]> wrote:
> The ieee80211_ops::sta_rc_update must be atomic, because
> ieee80211_chan_bw_change() holds rcu_read lock while calling
> drv_sta_rc_update(), so create a work to do original things.
>
> Voluntary context switch within RCU read-side critical section!
> WARNING: CPU: 0 PID: 4621 at kernel/rcu/tree_plugin.h:318
> rcu_note_context_switch+0x571/0x5d0
> CPU: 0 PID: 4621 Comm: kworker/u16:2 Tainted: G W OE
> Workqueue: phy3 ieee80211_chswitch_work [mac80211]
> RIP: 0010:rcu_note_context_switch+0x571/0x5d0
> Call Trace:
> <TASK>
> __schedule+0xb0/0x1460
> ? __mod_timer+0x116/0x360
> schedule+0x5a/0xc0
> schedule_timeout+0x87/0x150
> ? trace_raw_output_tick_stop+0x60/0x60
> wait_for_completion_timeout+0x7b/0x140
> usb_start_wait_urb+0x82/0x160 [usbcore
> usb_control_msg+0xe3/0x140 [usbcore
> rtw_usb_read+0x88/0xe0 [rtw_usb
> rtw_usb_read8+0xf/0x10 [rtw_usb
> rtw_fw_send_h2c_command+0xa0/0x170 [rtw_core
> rtw_fw_send_ra_info+0xc9/0xf0 [rtw_core
> drv_sta_rc_update+0x7c/0x160 [mac80211
> ieee80211_chan_bw_change+0xfb/0x110 [mac80211
> ieee80211_change_chanctx+0x38/0x130 [mac80211
> ieee80211_vif_use_reserved_switch+0x34e/0x900 [mac80211
> ieee80211_link_use_reserved_context+0x88/0xe0 [mac80211
> ieee80211_chswitch_work+0x95/0x170 [mac80211
> process_one_work+0x201/0x410
> worker_thread+0x4a/0x3b0
> ? process_one_work+0x410/0x410
> kthread+0xe1/0x110
> ? kthread_complete_and_exit+0x20/0x20
> ret_from_fork+0x1f/0x30
> </TASK>
>
> Cc: [email protected]
> Fixes: c1edc86472fc ("rtw88: add ieee80211:sta_rc_update ops")
> Reported-by: Larry Finger <[email protected]>
> Link: https://lore.kernel.org/linux-wireless/[email protected]/T/#t
> Signed-off-by: Ping-Ke Shih <[email protected]>
> Tested-by: Larry Finger <[email protected]>
Patch applied to wireless.git, thanks.
bcafcb959a57 wifi: rtw88: use work to update rate to avoid RCU warning
--
https://patchwork.kernel.org/project/linux-wireless/patch/[email protected]/
https://wireless.wiki.kernel.org/en/developers/documentation/submittingpatches