qcacld-3.0: Move fw down handling to psoc shutdown

As time goes by, more and more logic gets added to the firmware down
indication handler. Generally, there isn't a good reason why this logic
can't or shouldn't be handled with the rest of the subsystem restart
(SSR) cleanup code during the psoc shutdown phase. Additionally, the
firmware down indication can come in hardware interrupt context on some
platforms. This is incompatible with the current mutex-grabbing design.

On order to unify the SSR cleanup logic and support platforms which send
the firmware down indication in hardware interrupt context, move
processing currently done during firmware down handling to psoc shutdown
instead.

Change-Id: Ie1dea835eca5bad1ac3647a0da544d2c51c24194
CRs-Fixed: 2345287

core/hdd/src/wlan_hdd_driver_ops.c

@@ -450,7 +450,6 @@ static int hdd_soc_recovery_reinit(struct device *dev,
 	hdd_info("re-probing driver");
 
 	hdd_soc_load_lock(dev, eHDD_DRV_OP_REINIT);
-	cds_set_recovery_in_progress(true);
 	cds_set_driver_in_bad_state(false);
 
 	errno = hdd_init_qdf_ctx(dev, bdev, bus_type, bid);
@@ -476,7 +475,6 @@ assert_fail_count:
 
 unlock:
 	cds_set_driver_in_bad_state(true);
-	cds_set_recovery_in_progress(false);
 	hdd_soc_load_unlock(dev);
 
 	return check_for_probe_defer(errno);
@@ -564,6 +562,37 @@ static void hdd_send_hang_reason(void)
 	wlan_hdd_send_hang_reason_event(hdd_ctx, reason);
 }
 
+/**
+ * hdd_psoc_shutdown_notify() - notify the various interested parties that the
+ *	soc is starting recovery shutdown
+ * @hdd_ctx: the HDD context corresponding to the soc undergoing shutdown
+ *
+ * Return: None
+ */
+static void hdd_psoc_shutdown_notify(struct hdd_context *hdd_ctx)
+{
+	/* Notify external threads currently waiting on firmware by forcefully
+	 * completing waiting events with a "reset" status. This will cause the
+	 * event to fail early instead of timing out.
+	 */
+	qdf_complete_wait_events();
+
+	wlan_cfg80211_cleanup_scan_queue(hdd_ctx->pdev, NULL);
+
+	if (ucfg_ipa_is_enabled()) {
+		ucfg_ipa_uc_force_pipe_shutdown(hdd_ctx->pdev);
+
+		if (pld_is_fw_rejuvenate(hdd_ctx->parent_dev))
+			ucfg_ipa_fw_rejuvenate_send_msg(hdd_ctx->pdev);
+	}
+
+	cds_shutdown_notifier_call();
+	cds_shutdown_notifier_purge();
+
+	hdd_wlan_ssr_shutdown_event();
+	hdd_send_hang_reason();
+}
+
 /**
  * hdd_soc_recovery_shutdown() - perform PDR/SSR SoC shutdown
  *
@@ -579,10 +608,29 @@ static void hdd_send_hang_reason(void)
  */
 static void hdd_soc_recovery_shutdown(void)
 {
+	struct hdd_context *hdd_ctx;
 	void *hif_ctx;
 
+	/* recovery starts via firmware down indication; ensure we got one */
+	QDF_BUG(cds_is_driver_recovering());
+
+	hdd_ctx = cds_get_context(QDF_MODULE_ID_HDD);
+	if (!hdd_ctx) {
+		hdd_err("hdd_ctx is null");
+		return;
+	}
+
+	/* cancel/flush any pending/active idle shutdown work */
+	hdd_psoc_idle_timer_stop(hdd_ctx);
+
+	/* nothing to do if the soc is already unloaded */
+	if (hdd_ctx->driver_status == DRIVER_MODULES_CLOSED) {
+		hdd_info("Driver modules are already closed");
+		return;
+	}
+
 	if (cds_is_load_or_unload_in_progress()) {
-		hdd_err("Load/unload in progress, ignore SSR shutdown");
+		hdd_info("Load/unload in progress, ignore SSR shutdown");
 		return;
 	}
 
@@ -595,21 +643,7 @@ static void hdd_soc_recovery_shutdown(void)
 	/* mask the host controller interrupts */
 	hif_mask_interrupt_call(hif_ctx);
 
-	/*
-	 * Force Complete all the wait events before shutdown.
-	 * This is done at "hdd_cleanup_on_fw_down" api also to clean up the
-	 * wait events of north bound apis.
-	 * In case of SSR there is significant dely between FW down event and
-	 * wlan_hdd_shutdown, there is a possibility of race condition that
-	 * these wait events gets complete at "hdd_cleanup_on_fw_down" and
-	 * some new event is added before shutdown.
-	 */
-	qdf_complete_wait_events();
-
-	/* this is for cases, where shutdown invoked from platform */
-	cds_set_recovery_in_progress(true);
-	hdd_wlan_ssr_shutdown_event();
-	hdd_send_hang_reason();
+	hdd_psoc_shutdown_notify(hdd_ctx);
 
 	if (!cds_wait_for_external_threads_completion(__func__))
 		hdd_err("Host is not ready for SSR, attempting anyway");
@@ -1475,75 +1509,6 @@ static void wlan_hdd_pld_notify_handler(struct device *dev,
 	wlan_hdd_notify_handler(state);
 }
 
-static void wlan_hdd_purge_notifier(void)
-{
-	struct hdd_context *hdd_ctx;
-
-	hdd_enter();
-
-	hdd_ctx = cds_get_context(QDF_MODULE_ID_HDD);
-	if (!hdd_ctx) {
-		hdd_err("hdd_ctx is null");
-		return;
-	}
-
-	hdd_psoc_idle_timer_stop(hdd_ctx);
-
-	mutex_lock(&hdd_ctx->iface_change_lock);
-	cds_shutdown_notifier_call();
-	cds_shutdown_notifier_purge();
-	mutex_unlock(&hdd_ctx->iface_change_lock);
-
-	hdd_exit();
-}
-
-static void __hdd_firmware_down_handler(void)
-{
-	struct hdd_context *hdd_ctx;
-
-	if (cds_get_driver_state() == CDS_DRIVER_STATE_UNINITIALIZED)
-		return;
-
-	if (cds_is_driver_loading())
-		return;
-
-	hdd_ctx = cds_get_context(QDF_MODULE_ID_HDD);
-	if (!hdd_ctx) {
-		hdd_err("hdd_ctx is null");
-		return;
-	}
-
-	if (hdd_ctx->driver_status == DRIVER_MODULES_CLOSED) {
-		hdd_info("Driver modules are already closed");
-		return;
-	}
-
-	cds_set_target_ready(false);
-	qdf_complete_wait_events();
-	wlan_cfg80211_cleanup_scan_queue(hdd_ctx->pdev, NULL);
-
-	if (ucfg_ipa_is_enabled()) {
-		ucfg_ipa_uc_force_pipe_shutdown(hdd_ctx->pdev);
-
-		if (pld_is_fw_rejuvenate(hdd_ctx->parent_dev))
-			ucfg_ipa_fw_rejuvenate_send_msg(hdd_ctx->pdev);
-	}
-}
-
-static void hdd_firmware_down_handler(void)
-{
-	hdd_info("Received firmware down indication");
-
-	cds_set_target_ready(false);
-	cds_set_recovery_in_progress(true);
-
-	mutex_lock(&hdd_init_deinit_lock);
-	__hdd_firmware_down_handler();
-	mutex_unlock(&hdd_init_deinit_lock);
-
-	wlan_hdd_purge_notifier();
-}
-
 /**
  * wlan_hdd_pld_uevent() - platform uevent handler
  * @dev: device on which the uevent occurred
@@ -1554,13 +1519,30 @@ static void hdd_firmware_down_handler(void)
 static void
 wlan_hdd_pld_uevent(struct device *dev, struct pld_uevent_data *event_data)
 {
-	hdd_debug("Received uevent %d", event_data->uevent);
-
 	switch (event_data->uevent) {
 	case PLD_FW_DOWN:
-		hdd_firmware_down_handler();
+		hdd_info("Received firmware down indication");
+
+		/* NOTE! SSR cleanup logic goes in pld shutdown, not here */
+
+		cds_set_target_ready(false);
+		cds_set_recovery_in_progress(true);
+
+		/* SSR cleanup happens in pld shutdown, which is serialized by
+		 * the platform driver. Other operations are also serialized by
+		 * platform driver, such as probe, remove, and reinit. If the
+		 * firmware goes down during one of these operations, the driver
+		 * would normally have to wait for a timeout before shutdown
+		 * could begin. Instead, forcefully complete events waiting on
+		 * firmware with a "reset" status to avoid waiting to time out
+		 * on a firmware we already know is down.
+		 */
+		qdf_complete_wait_events();
+
 		break;
 	default:
+		/* other events intentionally not handled */
+		hdd_debug("Received uevent %d", event_data->uevent);
 		break;
 	}
 }