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From:   Zijun Hu <zijuhu@codeaurora.org>
To:     marcel@holtmann.org, johan.hedberg@gmail.com, luiz.dentz@gmail.com
Cc:     linux-kernel@vger.kernel.org, linux-bluetooth@vger.kernel.org,
        linux-arm-msm@vger.kernel.org, c-hbandi@codeaurora.org,
        hemantg@codeaurora.org, rjliao@codeaurora.org,
        zijuhu@codeaurora.org, tjiang@codeaurora.org,
        Zijun Hu <quic_zijuhu@quicinc.com>
Subject: [PATCH v3] Bluetooth: btusb: Improve stability for QCA devices
Date:   Mon, 14 Feb 2022 18:35:35 +0800
Message-Id: <1644834935-23189-1-git-send-email-zijuhu@codeaurora.org>
Precedence: bulk

From: Zijun Hu <quic_zijuhu@quicinc.com>

Controller will reset after NVM is downloaded for QCA
device, so wait a moment for reset Done then go ahead
to improve stability.

Signed-off-by: Zijun Hu <quic_zijuhu@quicinc.com>
---
 drivers/bluetooth/btusb.c | 8 ++++++++
 1 file changed, 8 insertions(+)

diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index e03dfbd92fcc..4932c0bb6662 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -2994,6 +2994,7 @@ static int btusb_set_bdaddr_wcn6855(struct hci_dev *hdev,
 #define QCA_PATCH_UPDATED	0x80
 #define QCA_DFU_TIMEOUT		3000
 #define QCA_FLAG_MULTI_NVM      0x80
+#define QCA_BT_RESET_WAIT_MS    100
 
 #define WCN6855_2_0_RAM_VERSION_GF 0x400c1200
 #define WCN6855_2_1_RAM_VERSION_GF 0x400c1211
@@ -3320,6 +3321,13 @@ static int btusb_setup_qca(struct hci_dev *hdev)
 		err = btusb_setup_qca_load_nvm(hdev, &ver, info);
 		if (err < 0)
 			return err;
+
+		/* WCN6855 2.1 will reset to apply firmware downloaded here, so
+		 * wait ~100ms for reset Done then go ahead, otherwise, it maybe
+		 * cause potential enable failure.
+		 */
+		if (info->rom_version == 0x00130201)
+			msleep(QCA_BT_RESET_WAIT_MS);
 	}
 
 	return 0;
-- 
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