wifi: ath12k: indicate to mac80211 scan complete with aborted flag for ATH12K_SCAN_ST...

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/ath12k/wcn7850\ 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 ath12k_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. __ath12k_mac_scan_finish() which is called from
ath12k_core_halt() is one step of recovery, it will not call
ieee80211_scan_completed() by logic currently because the scan state is
ATH12K_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
ATH12K_SCAN_STARTING to allow recovery from scan failed with "Device or
resource busy (-16)" after wlan recovery.

Tested-on: WCN7850 hw2.0 PCI WLAN.HMT.1.0-03427-QCAHMTSWPL_V1.0_V2.0_SILICONZ-1.15378.4

Signed-off-by: Wen Gong <quic_wgong@quicinc.com>
Acked-by: Jeff Johnson <quic_jjohnson@quicinc.com>
Signed-off-by: Kalle Valo <quic_kvalo@quicinc.com>
Link: https://lore.kernel.org/r/20230905105947.10369-1-quic_wgong@quicinc.com

diff --git a/drivers/net/wireless/ath/ath12k/mac.c b/drivers/net/wireless/ath/ath12k/mac.c
index 486d062b0a76e7f14ad1a63bb34f78718406851a..ed5d3edf6b9249bd4e5f0de2fbc99204e566f9a8 100644 (file)
--- a/drivers/net/wireless/ath/ath12k/mac.c
+++ b/drivers/net/wireless/ath/ath12k/mac.c
@@ -2780,18 +2780,21 @@ void __ath12k_mac_scan_finish(struct ath12k *ar)
                break;
        case ATH12K_SCAN_RUNNING:
        case ATH12K_SCAN_ABORTING:
+               if (ar->scan.is_roc && ar->scan.roc_notify)
+                       ieee80211_remain_on_channel_expired(ar->hw);
+               fallthrough;
+       case ATH12K_SCAN_STARTING:
                if (!ar->scan.is_roc) {
                        struct cfg80211_scan_info info = {
-                               .aborted = (ar->scan.state ==
-                                           ATH12K_SCAN_ABORTING),
+                               .aborted = ((ar->scan.state ==
+                                           ATH12K_SCAN_ABORTING) ||
+                                           (ar->scan.state ==
+                                           ATH12K_SCAN_STARTING)),
                        };
 
                        ieee80211_scan_completed(ar->hw, &info);
-               } else if (ar->scan.roc_notify) {
-                       ieee80211_remain_on_channel_expired(ar->hw);
                }
-               fallthrough;
-       case ATH12K_SCAN_STARTING:
+
                ar->scan.state = ATH12K_SCAN_IDLE;
                ar->scan_channel = NULL;
                ar->scan.roc_freq = 0;