wifi: ath10k: Avoid vdev delete timeout when firmware is already down

In some scenarios, the firmware may be stopped before the interface is
removed, either due to a crash or because the remoteproc (e.g., MPSS)
is shut down early during system reboot or shutdown.

This leads to a delay during interface teardown, as the driver waits for
a vdev delete response that never arrives, eventually timing out.

Example (SNOC):
$ echo stop > /sys/class/remoteproc/remoteproc0/state
[ 71.64] remoteproc remoteproc0: stopped remote processor modem
$ reboot
[ 74.84] ath10k_snoc c800000.wifi: failed to transmit packet, dropping: -108
[ 74.84] ath10k_snoc c800000.wifi: failed to submit frame: -108
[...]
[ 82.39] ath10k_snoc c800000.wifi: Timeout in receiving vdev delete response

To avoid this, skip waiting for the vdev delete response if the firmware is
already marked as unreachable (`ATH10K_FLAG_CRASH_FLUSH`), similar to how
`ath10k_mac_wait_tx_complete()` and `ath10k_vdev_setup_sync()` handle this case.

Signed-off-by: Loic Poulain <[email protected]>
Link: https://patch.msgid.link/[email protected]
Signed-off-by: Jeff Johnson <[email protected]>

Author: Loic Poulain

drivers/net/wireless/ath/ath10k/mac.c

@@ -4,6 +4,7 @@
  * Copyright (c) 2011-2017 Qualcomm Atheros, Inc.
  * Copyright (c) 2018-2019, The Linux Foundation. All rights reserved.
  * Copyright (c) 2021-2024 Qualcomm Innovation Center, Inc. All rights reserved.
+ * Copyright (c) Qualcomm Technologies, Inc. and/or its subsidiaries.
  */
 
 #include "mac.h"
@@ -1022,6 +1023,26 @@ static inline int ath10k_vdev_setup_sync(struct ath10k *ar)
 	return ar->last_wmi_vdev_start_status;
 }
 
+static inline int ath10k_vdev_delete_sync(struct ath10k *ar)
+{
+	unsigned long time_left;
+
+	lockdep_assert_held(&ar->conf_mutex);
+
+	if (!test_bit(WMI_SERVICE_SYNC_DELETE_CMDS, ar->wmi.svc_map))
+		return 0;
+
+	if (test_bit(ATH10K_FLAG_CRASH_FLUSH, &ar->dev_flags))
+		return -ESHUTDOWN;
+
+	time_left = wait_for_completion_timeout(&ar->vdev_delete_done,
+						ATH10K_VDEV_DELETE_TIMEOUT_HZ);
+	if (time_left == 0)
+		return -ETIMEDOUT;
+
+	return 0;
+}
+
 static int ath10k_monitor_vdev_start(struct ath10k *ar, int vdev_id)
 {
 	struct cfg80211_chan_def *chandef = NULL;
@@ -5900,7 +5921,6 @@ static void ath10k_remove_interface(struct ieee80211_hw *hw,
 	struct ath10k *ar = hw->priv;
 	struct ath10k_vif *arvif = (void *)vif->drv_priv;
 	struct ath10k_peer *peer;
-	unsigned long time_left;
 	int ret;
 	int i;
 
@@ -5940,13 +5960,10 @@ static void ath10k_remove_interface(struct ieee80211_hw *hw,
 		ath10k_warn(ar, "failed to delete WMI vdev %i: %d\n",
 			    arvif->vdev_id, ret);
 
-	if (test_bit(WMI_SERVICE_SYNC_DELETE_CMDS, ar->wmi.svc_map)) {
-		time_left = wait_for_completion_timeout(&ar->vdev_delete_done,
-							ATH10K_VDEV_DELETE_TIMEOUT_HZ);
-		if (time_left == 0) {
-			ath10k_warn(ar, "Timeout in receiving vdev delete response\n");
-			goto out;
-		}
+	ret = ath10k_vdev_delete_sync(ar);
+	if (ret) {
+		ath10k_warn(ar, "Error in receiving vdev delete response: %d\n", ret);
+		goto out;
 	}
 
 	/* Some firmware revisions don't notify host about self-peer removal