BACKPORT: driver: bluetooth: hci_qca: Fix SSR (SubSystem Restart) fail when BT_EN is pulled up by hw

drivers/bluetooth/hci_qca.c

@@ -1653,25 +1653,40 @@ static void qca_hw_error(struct hci_dev *hdev, u8 code)
 		skb_queue_purge(&qca->rx_memdump_q);
 	}
 
-	clear_bit(QCA_HW_ERROR_EVENT, &qca->flags);
-
 	/*
-	 * If the SoC always enables the bt_en pin via hardware and the driver
-	 * cannot control the bt_en pin of the SoC chip, then during SSR,
-	 * the QCA_SSR_TRIGGERED and QCA_IBS_DISABLED bits cannot be cleared.
-	 * This leads to a reset command timeout failure.
+	 * If the BT chip's bt_en pin is connected to a 3.3V power supply via
+	 * hardware and always stays high, driver cannot control the bt_en pin.
+	 * As a result, during SSR (SubSystem Restart), QCA_SSR_TRIGGERED and
+	 * QCA_IBS_DISABLED flags cannot be cleared, which leads to a reset
+	 * command timeout.
+	 * Add an msleep delay to ensure controller completes the SSR process.
+	 *
+	 * Host will not download the firmware after SSR, controller to remain
+	 * in the IBS_WAKE state, and the host needs to synchronize with it
 	 *
-	 * To address this, clear QCA_SSR_TRIGGERED and QCA_IBS_DISABLED bits
-	 * after the coredump collection is complete.
-	 * Also, add msleep delay to wait for controller to complete SSR.
+	 * Since the bluetooth chip has been reset, clear the memdump state.
 	 */
 	if (!hci_test_quirk(hu->hdev, HCI_QUIRK_NON_PERSISTENT_SETUP)) {
+		/*
+		 * When the SSR (SubSystem Restart) duration exceeds 2 seconds,
+		 * it triggers host tx_idle_delay, which sets host TX state
+		 * to sleep. Reset tx_idle_timer after SSR to prevent
+		 * host enter TX IBS_Sleep mode.
+		 */
+		mod_timer(&qca->tx_idle_timer, jiffies +
+				  msecs_to_jiffies(qca->tx_idle_delay));
+
+		/* Controller reset completion time is 50ms */
+		msleep(50);
+
 		clear_bit(QCA_SSR_TRIGGERED, &qca->flags);
 		clear_bit(QCA_IBS_DISABLED, &qca->flags);
+
 		qca->tx_ibs_state = HCI_IBS_TX_AWAKE;
 		qca->memdump_state = QCA_MEMDUMP_IDLE;
-		msleep(50);
 	}
+
+	clear_bit(QCA_HW_ERROR_EVENT, &qca->flags);
 }
 
 static void qca_reset(struct hci_dev *hdev)