[PATCH 4.4 121/188] Bluetooth: btusb: fix bt fiwmare downloading failure issue for qca btsoc.

[Greg Kroah-Hartman]

From: Tim Jiang <tjiang@xxxxxxxxxxxxxx>

[ Upstream commit 4f00bfb372674d586c4a261bfc595cbce101fbb6 ]

This is btsoc timing issue, after host start to downloading bt firmware,
ep2 need time to switch from function acl to function dfu, so host add
20ms delay as workaround.

Signed-off-by: Tim Jiang <tjiang@xxxxxxxxxxxxxx>
Signed-off-by: Marcel Holtmann <marcel@xxxxxxxxxxxx>
Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx>
---
 drivers/bluetooth/btusb.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index 7039a58a6a4e..3d62f17111cb 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -2555,6 +2555,11 @@ static int btusb_setup_qca_download_fw(struct hci_dev *hdev,
 	sent += size;
 	count -= size;
 
+	/* ep2 need time to switch from function acl to function dfu,
+	 * so we add 20ms delay here.
+	 */
+	msleep(20);
+
 	while (count) {
 		size = min_t(size_t, count, QCA_DFU_PACKET_LEN);
 
-- 
2.30.2