Scan failure can not be recovered from when running a loop of the
following steps:
1. run scan: "iw wlan scan".
2. run command: echo assert > /sys/kernel/debug/ath11k/qca6490\ hw2.0/simulate_fw_crash
immediately after step 1.
result:
scan failed and can not recover even when wlan recovery succeeds:
command failed: Device or resource busy (-16)
reason:
When scan arrives, WMI_START_SCAN_CMDID is sent to the firmware and
function ath11k_mac_op_hw_scan() returns, then simulate_fw_crash arrives
and the scan started event does not arrive, and then it starts to do
recovery of wlan. __ath11k_mac_scan_finish() which is called from
ath11k_core_halt() is one step of recovery, it will not call
ieee80211_scan_completed() by logic currently because the scan state is
ATH11K_SCAN_STARTING. Thus it leads the scan not being completed in
mac80211, and leads all consecutive scans failing with -EBUSY in
nl80211_trigger_scan even after wlan recovery success.
Indicate scan complete with aborted flag to mac80211 for
ATH11K_SCAN_STARTING to allow recovery from scan failed with "Device or
resource busy (-16)" after wlan recovery.
Tested-on: WCN6855 hw2.0 PCI WLAN.HSP.1.1-01720.1-QCAHSPSWPL_V1_V2_SILICONZ_LITE-1
Signed-off-by: Wen Gong <wgong@codeaurora.org>
Signed-off-by: Jouni Malinen <jouni@codeaurora.org>
Signed-off-by: Kalle Valo <kvalo@codeaurora.org>
Link: https://lore.kernel.org/r/20210914164226.38843-3-jouni@codeaurora.org
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