[PATCH v4 0/3] wifi: rtw88: firmware recovery fixes and LPS hang handling

[PATCH v4 0/3] wifi: rtw88: firmware recovery fixes and LPS hang handling

[Kalpesh Solanki]

This series addresses firmware recovery robustness and LPS hang handling
in rtw88 based on review feedback from Luka Gejak and Ping-Ke Shih.

Patch 1/2 from the v2 series (DMI quirk for HP Laptop 15s-fr5xxx) was
already applied to rtw-next. The previous LPS leave recovery patch was
dropped from rtw-next by Ping-Ke Shih for respin.

This v4 series splits the recovery fixes into three focused patches:

1. Patch 1/3: Clear RTW_FLAG_RESTARTING on stop and start failure.
   mac80211's drv_stop() skips local->ops->stop() when local->started
   is false (such as after a failed drv_start()). If rtw_core_start()
   fails during restart, clearing the flag only in rtw_ops_stop() left
   it permanently set. We now clear RTW_FLAG_RESTARTING in both
   rtw_ops_stop() and in rtw_ops_start() upon rtw_core_start() failure.

2. Patch 2/3: Skip already reset station in rtw_sta_remove().
   During station disconnect (e.g., ieee80211_set_disassoc()), mac80211
   leaves LPS before removing the AP station. If recovery is triggered by
   LPS leave failure, __fw_recovery_work() removes all stations via
   rtw_reset_sta_iter(). When mac80211 subsequently calls
   rtw_ops_sta_remove(), rtw_sta_remove() ran a second time, resulting in
   a double free of si->mask and underflow of rtwdev->sta_cnt. We check
   si->vif at entry and clear si->vif and si->mask upon removal.

3. Patch 3/3: Trigger firmware recovery only after consecutive LPS leave
   failures on PCI.
   Restricts recovery to PCI devices (rtw_hci_type == RTW_HCI_TYPE_PCIE)
   because USB (usb_control_msg()) and SDIO (sdio_claim_host()) sleep,
   which triggers a "scheduling while atomic" panic under
   local->key_lock during key clearing in __fw_recovery_work(). Retains
   rtw_fw_dump_dbg_info() on the first failure (guarded by RTW_DBG_FW),
   and requires 3 consecutive timeouts (RTW_PS_HANG_MAX_CNT) before
   triggering hardware recovery. ps_hang_cnt is reset on success and in
   rtw_core_start().

Changes in v4:
- In patch 1/3: Also clear RTW_FLAG_RESTARTING in rtw_ops_start() if
  rtw_core_start() fails.
- Add patch 2/3: Prevent double free and sta_cnt underflow in
  rtw_sta_remove() when recovery races with station disconnect.
- In patch 3/3:
  - Keep rtw_fw_dump_dbg_info() in place on first failure.
  - Restrict firmware recovery invocation to PCIe devices to prevent
    scheduling while atomic panic on USB and SDIO.
  - Explicitly check rtw_hci_type() in rtw_fw_recovery().

Changes in v3:
- Note: v2 patch 1/2 (DMI quirk) is already applied in rtw-next.
- Add patch 1/2 to clear RTW_FLAG_RESTARTING in rtw_ops_stop()
  with Fixes tag.
- In patch 2/2:
  - Count consecutive failures before triggering recovery
    (RTW_PS_HANG_MAX_CNT = 3).
  - Reset ps_hang_cnt on successful LPS leave and in rtw_core_start().
  - Suppress raw register dump on transient failures to avoid log spam.

Changes in v2:
- Rebase on top of rtw-next.

Kalpesh Solanki (3):
  wifi: rtw88: clear RTW_FLAG_RESTARTING on stop and start failure
  wifi: rtw88: skip already reset station in rtw_sta_remove()
  wifi: rtw88: ps: trigger firmware recovery only after consecutive LPS
    leave failures on PCI

 drivers/net/wireless/realtek/rtw88/mac80211.c |  3 +++
 drivers/net/wireless/realtek/rtw88/main.c     | 10 ++++++++++
 drivers/net/wireless/realtek/rtw88/main.h     |  1 +
 drivers/net/wireless/realtek/rtw88/ps.c       |  7 +++++++
 drivers/net/wireless/realtek/rtw88/ps.h       |  1 +
 5 files changed, 22 insertions(+)

-- 
2.53.0

[PATCH v4 1/3] wifi: rtw88: clear RTW_FLAG_RESTARTING on stop and start failure

[Kalpesh Solanki]

When mac80211 stops or suspends the device without WoWLAN,
drv_reconfig_complete() is never invoked with
IEEE80211_RECONFIG_TYPE_RESTART. If firmware recovery was in flight
during this transition, RTW_FLAG_RESTARTING remains set permanently,
blocking all subsequent firmware recoveries until the module is reloaded.

Similarly, if rtw_core_start() fails during drv_start() in a recovery
restart, local->started remains false. When mac80211 cleans up via
cfg80211_shutdown_all_interfaces(), drv_stop() returns early without
calling rtw_ops_stop(), leaving RTW_FLAG_RESTARTING set permanently on
hardware that failed to recover.

Clear RTW_FLAG_RESTARTING in rtw_ops_stop(), as well as in
rtw_ops_start() when rtw_core_start() returns an error, ensuring the
driver always exits the restarting state on error or teardown.

Fixes: 5c831644e1f4 ("rtw88: handle and recover when firmware crash")
Cc: stable@vger.kernel.org
Signed-off-by: Kalpesh Solanki <skalpesh942@gmail.com>
---
 drivers/net/wireless/realtek/rtw88/mac80211.c | 3 +++
 1 file changed, 3 insertions(+)

diff --git a/drivers/net/wireless/realtek/rtw88/mac80211.c b/drivers/net/wireless/realtek/rtw88/mac80211.c
index 5e40cf06a9e..ffd86f08185 100644
--- a/drivers/net/wireless/realtek/rtw88/mac80211.c
+++ b/drivers/net/wireless/realtek/rtw88/mac80211.c
@@ -57,6 +57,8 @@ static int rtw_ops_start(struct ieee80211_hw *hw)
 
 	mutex_lock(&rtwdev->mutex);
 	ret = rtw_core_start(rtwdev);
+	if (ret)
+		clear_bit(RTW_FLAG_RESTARTING, rtwdev->flags);
 	mutex_unlock(&rtwdev->mutex);
 
 	return ret;
@@ -67,6 +69,7 @@ static void rtw_ops_stop(struct ieee80211_hw *hw, bool suspend)
 	struct rtw_dev *rtwdev = hw->priv;
 
 	mutex_lock(&rtwdev->mutex);
+	clear_bit(RTW_FLAG_RESTARTING, rtwdev->flags);
 	rtw_core_stop(rtwdev);
 	mutex_unlock(&rtwdev->mutex);
 }
-- 
2.53.0

[PATCH v4 2/3] wifi: rtw88: skip already reset station in rtw_sta_remove()

[Kalpesh Solanki]

During firmware recovery, __fw_recovery_work() iterates over all
stations and invokes rtw_sta_remove() via rtw_reset_sta_iter().

If recovery is triggered concurrently with station teardown (such as
during ieee80211_set_disassoc() where mac80211 leaves LPS before
removing the AP station), rtw_ops_sta_remove() is subsequently called
for the same station. This causes rtw_sta_remove() to execute twice,
leading to a double free of si->mask and an underflow of rtwdev->sta_cnt.

Check si->vif in rtw_sta_remove() and return early if the station was
already reset, setting si->vif and si->mask to NULL upon removal.

Fixes: 5c831644e1f4 ("rtw88: handle and recover when firmware crash")
Cc: stable@vger.kernel.org
Signed-off-by: Kalpesh Solanki <skalpesh942@gmail.com>
---
 drivers/net/wireless/realtek/rtw88/main.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/net/wireless/realtek/rtw88/main.c b/drivers/net/wireless/realtek/rtw88/main.c
index f7708ad17b6..a74f199a93a 100644
--- a/drivers/net/wireless/realtek/rtw88/main.c
+++ b/drivers/net/wireless/realtek/rtw88/main.c
@@ -384,6 +384,9 @@ void rtw_sta_remove(struct rtw_dev *rtwdev, struct ieee80211_sta *sta,
 	struct ieee80211_vif *vif = si->vif;
 	int i;
 
+	if (!vif)
+		return;
+
 	cancel_work_sync(&si->rc_work);
 
 	if (vif->type != NL80211_IFTYPE_STATION || sta->tdls)
@@ -395,8 +398,10 @@ void rtw_sta_remove(struct rtw_dev *rtwdev, struct ieee80211_sta *sta,
 		rtw_txq_cleanup(rtwdev, sta->txq[i]);
 
 	kfree(si->mask);
+	si->mask = NULL;
 
 	rtwdev->sta_cnt--;
+	si->vif = NULL;
 	rtw_dbg(rtwdev, RTW_DBG_STATE, "sta %pM with macid %d left\n",
 		sta->addr, si->mac_id);
 }
-- 
2.53.0

[PATCH v4 3/3] wifi: rtw88: ps: trigger firmware recovery only after consecutive LPS leave failures on PCI

[Kalpesh Solanki]

A single timeout in rtw_fw_leave_lps_check() does not always indicate a
frozen firmware; in noisy RF environments or during beacon loss, the
802.11 null data frame ACK can be delayed or dropped. Immediately
triggering firmware recovery and a full hardware restart on a single
timeout causes unnecessary disconnections and kernel warning traces on
idle links.

Follow rtw89 by introducing a consecutive failure counter (ps_hang_cnt)
and only triggering rtw_fw_recovery() after RTW_PS_HANG_MAX_CNT (3)
consecutive failures. Reset the counter to 0 on every successful LPS
leave and in rtw_core_start() so that cold starts and hardware restarts
always begin with a clean slate.

Additionally, rtw_fw_recovery() clears keys via rtw_iterate_keys_atomic()
under a spinlock. On USB and SDIO, register writes in key clearing sleep
(via usb_control_msg() and sdio_claim_host()), which would trigger a
BUG: scheduling while atomic if executed. Because USB and SDIO do not
support firmware recovery, restrict rtw_fw_recovery() to PCI devices
via rtw_hci_type().

Signed-off-by: Kalpesh Solanki <skalpesh942@gmail.com>
---
 drivers/net/wireless/realtek/rtw88/main.c | 5 +++++
 drivers/net/wireless/realtek/rtw88/main.h | 1 +
 drivers/net/wireless/realtek/rtw88/ps.c   | 7 +++++++
 drivers/net/wireless/realtek/rtw88/ps.h   | 1 +
 4 files changed, 14 insertions(+)

diff --git a/drivers/net/wireless/realtek/rtw88/main.c b/drivers/net/wireless/realtek/rtw88/main.c
index a74f199a93a..7009f8ae3e5 100644
--- a/drivers/net/wireless/realtek/rtw88/main.c
+++ b/drivers/net/wireless/realtek/rtw88/main.c
@@ -638,6 +638,9 @@ static void rtw_reset_vif_iter(void *data, u8 *mac, struct ieee80211_vif *vif)
 
 void rtw_fw_recovery(struct rtw_dev *rtwdev)
 {
+	if (rtw_hci_type(rtwdev) != RTW_HCI_TYPE_PCIE)
+		return;
+
 	if (!test_bit(RTW_FLAG_RESTARTING, rtwdev->flags))
 		ieee80211_queue_work(rtwdev->hw, &rtwdev->fw_recovery_work);
 }
@@ -1536,6 +1539,8 @@ int rtw_core_start(struct rtw_dev *rtwdev)
 
 	set_bit(RTW_FLAG_RUNNING, rtwdev->flags);
 
+	rtwdev->ps_hang_cnt = 0;
+
 	return 0;
 }
 
diff --git a/drivers/net/wireless/realtek/rtw88/main.h b/drivers/net/wireless/realtek/rtw88/main.h
index 6ecbeb4ffe4..525f17590ad 100644
--- a/drivers/net/wireless/realtek/rtw88/main.h
+++ b/drivers/net/wireless/realtek/rtw88/main.h
@@ -2113,6 +2113,7 @@ struct rtw_dev {
 	/* lps power state & handler work */
 	struct rtw_lps_conf lps_conf;
 	bool ps_enabled;
+	u8 ps_hang_cnt;
 	bool beacon_loss;
 	struct completion lps_leave_check;
 
diff --git a/drivers/net/wireless/realtek/rtw88/ps.c b/drivers/net/wireless/realtek/rtw88/ps.c
index add5a20b843..fa3a4e476cf 100644
--- a/drivers/net/wireless/realtek/rtw88/ps.c
+++ b/drivers/net/wireless/realtek/rtw88/ps.c
@@ -166,6 +166,13 @@ static void rtw_fw_leave_lps_check(struct rtw_dev *rtwdev)
 		rtw_write32_clr(rtwdev, REG_TCR, BIT_PWRMGT_HWDATA_EN);
 		rtw_warn(rtwdev, "firmware failed to leave lps state\n");
 		rtw_fw_dump_dbg_info(rtwdev);
+
+		rtwdev->ps_hang_cnt++;
+		if (rtw_hci_type(rtwdev) == RTW_HCI_TYPE_PCIE &&
+		    rtwdev->ps_hang_cnt >= RTW_PS_HANG_MAX_CNT)
+			rtw_fw_recovery(rtwdev);
+	} else {
+		rtwdev->ps_hang_cnt = 0;
 	}
 }
 
diff --git a/drivers/net/wireless/realtek/rtw88/ps.h b/drivers/net/wireless/realtek/rtw88/ps.h
index 5ae83d2526c..b088fad7cd8 100644
--- a/drivers/net/wireless/realtek/rtw88/ps.h
+++ b/drivers/net/wireless/realtek/rtw88/ps.h
@@ -14,6 +14,7 @@
 
 #define LEAVE_LPS_TRY_CNT	5
 #define LEAVE_LPS_TIMEOUT	msecs_to_jiffies(100)
+#define RTW_PS_HANG_MAX_CNT	3
 
 int rtw_enter_ips(struct rtw_dev *rtwdev);
 int rtw_leave_ips(struct rtw_dev *rtwdev);
-- 
2.53.0