This enables prints for firmware download which can help automation
tests to verify firmware download functionality.

A new flag BTNXPUART_FW_DOWNLOAD_ABORT is added which handles the
situation where driver is removed while firmware download is in
progress.

This also adds a check before freeing the rx->skb in flush and close
functions to handle the kernel crash seen in case of firmware download
timeout.

Signed-off-by: Neeraj Sanjay Kale <neeraj.sanjaykale@nxp.com>
Tested-by: Guillaume Legoupil <guillaume.legoupil@nxp.com>
---
v2: Handle firmware download abort scenario. (Guillaume Legoupil)
v3: Minor corrections. Add details to commit message.
---
 drivers/bluetooth/btnxpuart.c | 67 +++++++++++++++++++++++------------
 1 file changed, 45 insertions(+), 22 deletions(-)

diff --git a/drivers/bluetooth/btnxpuart.c b/drivers/bluetooth/btnxpuart.c
index 0b93c2ff29e4..7aed5298ee6f 100644
--- a/drivers/bluetooth/btnxpuart.c
+++ b/drivers/bluetooth/btnxpuart.c
@@ -29,6 +29,7 @@
 #define BTNXPUART_CHECK_BOOT_SIGNATURE	3
 #define BTNXPUART_SERDEV_OPEN		4
 #define BTNXPUART_IR_IN_PROGRESS	5
+#define BTNXPUART_FW_DOWNLOAD_ABORT	6
 
 /* NXP HW err codes */
 #define BTNXPUART_IR_HW_ERR		0xb0
@@ -159,6 +160,7 @@ struct btnxpuart_dev {
 	u8 fw_name[MAX_FW_FILE_NAME_LEN];
 	u32 fw_dnld_v1_offset;
 	u32 fw_v1_sent_bytes;
+	u32 fw_dnld_v3_offset;
 	u32 fw_v3_offset_correction;
 	u32 fw_v1_expected_len;
 	u32 boot_reg_offset;
@@ -550,6 +552,7 @@ static int nxp_download_firmware(struct hci_dev *hdev)
 	nxpdev->fw_v1_sent_bytes = 0;
 	nxpdev->fw_v1_expected_len = HDR_LEN;
 	nxpdev->boot_reg_offset = 0;
+	nxpdev->fw_dnld_v3_offset = 0;
 	nxpdev->fw_v3_offset_correction = 0;
 	nxpdev->baudrate_changed = false;
 	nxpdev->timeout_changed = false;
@@ -564,14 +567,23 @@ static int nxp_download_firmware(struct hci_dev *hdev)
 					       !test_bit(BTNXPUART_FW_DOWNLOADING,
 							 &nxpdev->tx_state),
 					       msecs_to_jiffies(60000));
+
+	release_firmware(nxpdev->fw);
+	memset(nxpdev->fw_name, 0, sizeof(nxpdev->fw_name));
+
 	if (err == 0) {
-		bt_dev_err(hdev, "FW Download Timeout.");
+		bt_dev_err(hdev, "FW Download Timeout. offset: %d",
+				nxpdev->fw_dnld_v1_offset ?
+				nxpdev->fw_dnld_v1_offset :
+				nxpdev->fw_dnld_v3_offset);
 		return -ETIMEDOUT;
 	}
+	if (test_bit(BTNXPUART_FW_DOWNLOAD_ABORT, &nxpdev->tx_state)) {
+		bt_dev_err(hdev, "FW Download Aborted");
+		return -EINTR;
+	}
 
 	serdev_device_set_flow_control(nxpdev->serdev, true);
-	release_firmware(nxpdev->fw);
-	memset(nxpdev->fw_name, 0, sizeof(nxpdev->fw_name));
 
 	/* Allow the downloaded FW to initialize */
 	msleep(1200);
@@ -693,7 +705,7 @@ static int nxp_request_firmware(struct hci_dev *hdev, const char *fw_name)
 	if (!strlen(nxpdev->fw_name)) {
 		snprintf(nxpdev->fw_name, MAX_FW_FILE_NAME_LEN, "%s", fw_name);
 
-		bt_dev_dbg(hdev, "Request Firmware: %s", nxpdev->fw_name);
+		bt_dev_info(hdev, "Request Firmware: %s", nxpdev->fw_name);
 		err = request_firmware(&nxpdev->fw, nxpdev->fw_name, &hdev->dev);
 		if (err < 0) {
 			bt_dev_err(hdev, "Firmware file %s not found", nxpdev->fw_name);
@@ -781,7 +793,7 @@ static int nxp_recv_fw_req_v1(struct hci_dev *hdev, struct sk_buff *skb)
 	}
 
 	if (!len) {
-		bt_dev_dbg(hdev, "FW Downloaded Successfully: %zu bytes",
+		bt_dev_info(hdev, "FW Download Complete: %zu bytes",
 			   nxpdev->fw->size);
 		if (nxp_data->helper_fw_name && !nxpdev->helper_downloaded) {
 			nxpdev->helper_downloaded = true;
@@ -934,7 +946,7 @@ static int nxp_recv_fw_req_v3(struct hci_dev *hdev, struct sk_buff *skb)
 	}
 
 	if (req->len == 0) {
-		bt_dev_dbg(hdev, "FW Downloaded Successfully: %zu bytes",
+		bt_dev_info(hdev, "FW Download Complete: %zu bytes",
 			   nxpdev->fw->size);
 		clear_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state);
 		wake_up_interruptible(&nxpdev->fw_dnld_done_wait_q);
@@ -954,8 +966,9 @@ static int nxp_recv_fw_req_v3(struct hci_dev *hdev, struct sk_buff *skb)
 		goto free_skb;
 	}
 
-	serdev_device_write_buf(nxpdev->serdev, nxpdev->fw->data + offset -
-				nxpdev->fw_v3_offset_correction, len);
+	nxpdev->fw_dnld_v3_offset = offset - nxpdev->fw_v3_offset_correction;
+	serdev_device_write_buf(nxpdev->serdev, nxpdev->fw->data +
+				nxpdev->fw_dnld_v3_offset, len);
 
 free_skb:
 	kfree_skb(skb);
@@ -1037,7 +1050,7 @@ static int nxp_setup(struct hci_dev *hdev)
 		if (err < 0)
 			return err;
 	} else {
-		bt_dev_dbg(hdev, "FW already running.");
+		bt_dev_info(hdev, "FW already running.");
 		clear_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state);
 	}
 
@@ -1253,8 +1266,10 @@ static int btnxpuart_close(struct hci_dev *hdev)
 	ps_wakeup(nxpdev);
 	serdev_device_close(nxpdev->serdev);
 	skb_queue_purge(&nxpdev->txq);
-	kfree_skb(nxpdev->rx_skb);
-	nxpdev->rx_skb = NULL;
+	if (!IS_ERR_OR_NULL(nxpdev->rx_skb)) {
+		kfree_skb(nxpdev->rx_skb);
+		nxpdev->rx_skb = NULL;
+	}
 	clear_bit(BTNXPUART_SERDEV_OPEN, &nxpdev->tx_state);
 	return 0;
 }
@@ -1269,8 +1284,10 @@ static int btnxpuart_flush(struct hci_dev *hdev)
 
 	cancel_work_sync(&nxpdev->tx_work);
 
-	kfree_skb(nxpdev->rx_skb);
-	nxpdev->rx_skb = NULL;
+	if (!IS_ERR_OR_NULL(nxpdev->rx_skb)) {
+		kfree_skb(nxpdev->rx_skb);
+		nxpdev->rx_skb = NULL;
+	}
 
 	return 0;
 }
@@ -1385,16 +1402,22 @@ static void nxp_serdev_remove(struct serdev_device *serdev)
 	struct btnxpuart_dev *nxpdev = serdev_device_get_drvdata(serdev);
 	struct hci_dev *hdev = nxpdev->hdev;
 
-	/* Restore FW baudrate to fw_init_baudrate if changed.
-	 * This will ensure FW baudrate is in sync with
-	 * driver baudrate in case this driver is re-inserted.
-	 */
-	if (nxpdev->current_baudrate != nxpdev->fw_init_baudrate) {
-		nxpdev->new_baudrate = nxpdev->fw_init_baudrate;
-		nxp_set_baudrate_cmd(hdev, NULL);
+	if (is_fw_downloading(nxpdev)) {
+		set_bit(BTNXPUART_FW_DOWNLOAD_ABORT, &nxpdev->tx_state);
+		clear_bit(BTNXPUART_FW_DOWNLOADING, &nxpdev->tx_state);
+		wake_up_interruptible(&nxpdev->check_boot_sign_wait_q);
+		wake_up_interruptible(&nxpdev->fw_dnld_done_wait_q);
+	} else {
+		/* Restore FW baudrate to fw_init_baudrate if changed.
+		 * This will ensure FW baudrate is in sync with
+		 * driver baudrate in case this driver is re-inserted.
+		 */
+		if (nxpdev->current_baudrate != nxpdev->fw_init_baudrate) {
+			nxpdev->new_baudrate = nxpdev->fw_init_baudrate;
+			nxp_set_baudrate_cmd(hdev, NULL);
+		}
+		ps_cancel_timer(nxpdev);
 	}
-
-	ps_cancel_timer(nxpdev);
 	hci_unregister_dev(hdev);
 	hci_free_dev(hdev);
 }
-- 
2.34.1