[PATCH v4 4/5] Bluetooth: btusb: mediatek: reset the controller before downloading the fw

[sean.wang at kernel.org]

From: Hao Qin <hao.qin at mediatek.com>

Reset the controller before downloading the firmware to improve its
reliability. This includes situations like cold or warm reboots, ensuring
the controller is in its initial state before starting the firmware
download.

Co-developed-by: Sean Wang <sean.wang at mediatek.com>
Signed-off-by: Sean Wang <sean.wang at mediatek.com>
Co-developed-by: Chris Lu <chris.lu at mediatek.com>
Signed-off-by: Chris Lu <chris.lu at mediatek.com>
Signed-off-by: Hao Qin <hao.qin at mediatek.com>
---
v3: split from the v2 to make the patch do one thing in a patch and ensure
    the reset the controller only when we actually need it to avoid the
    regression on the time spent in opening the controller.
v4: rebase onto the latest code
---
 drivers/bluetooth/btusb.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index 76c52f2fe917..054e8c06bcf3 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -3175,6 +3175,13 @@ static int btusb_mtk_setup(struct hci_dev *hdev)
 	case 0x7922:
 	case 0x7961:
 	case 0x7925:
+		/* Reset the device to ensure it's in the initial state before
+		 * downloading the firmware to ensure.
+		 */
+
+		if (!test_bit(BTUSB_FIRMWARE_LOADED, &data->flags))
+			btusb_mtk_subsys_reset(hdev, dev_id);
+
 		btmtk_fw_get_filename(fw_bin_name, sizeof(fw_bin_name), dev_id,
 				      fw_version, fw_flavor);
 
@@ -3182,9 +3189,12 @@ static int btusb_mtk_setup(struct hci_dev *hdev)
 						btusb_mtk_hci_wmt_sync);
 		if (err < 0) {
 			bt_dev_err(hdev, "Failed to set up firmware (%d)", err);
+			clear_bit(BTUSB_FIRMWARE_LOADED, &data->flags);
 			return err;
 		}
 
+		set_bit(BTUSB_FIRMWARE_LOADED, &data->flags);
+
 		/* It's Device EndPoint Reset Option Register */
 		btusb_mtk_uhw_reg_write(data, MTK_EP_RST_OPT, MTK_EP_RST_IN_OUT_OPT);
 
-- 
2.25.1