[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(+)

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2.53.0