[PATCH v5 4/5] Bluetooth: btusb: mediatek: reset the controller before downloading the fw

[sean.wang@kernel.org]

From: Hao Qin <hao.qin@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@mediatek.com>
Signed-off-by: Sean Wang <sean.wang@mediatek.com>
Co-developed-by: Chris Lu <chris.lu@mediatek.com>
Signed-off-by: Chris Lu <chris.lu@mediatek.com>
Signed-off-by: Hao Qin <hao.qin@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
v5: no change
---
 drivers/bluetooth/btusb.c | 10 ++++++++++
 1 file changed, 10 insertions(+)

diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index 602456e94fdb..ddd5ca7596e5 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