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From:   Greg Kroah-Hartman <gregkh@linuxfoundation.org>
To:     linux-kernel@vger.kernel.org
Cc:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>,
        stable@vger.kernel.org, Tim Jiang <tjiang@codeaurora.org>,
        Marcel Holtmann <marcel@holtmann.org>,
        Sasha Levin <sashal@kernel.org>
Subject: [PATCH 4.9 155/245] Bluetooth: btusb: fix bt fiwmare downloading failure issue for qca btsoc.
Date:   Mon, 19 Jul 2021 16:51:37 +0200
Message-Id: <20210719144945.409865923@linuxfoundation.org>
In-Reply-To: <20210719144940.288257948@linuxfoundation.org>
References: <20210719144940.288257948@linuxfoundation.org>
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From: Tim Jiang <tjiang@codeaurora.org>

[ 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@codeaurora.org>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/bluetooth/btusb.c | 5 +++++
 1 file changed, 5 insertions(+)

diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index 4e3b24a0511f..30c09b9ddbf0 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -2508,6 +2508,11 @@ 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