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From:   Tedd Ho-Jeong An <hj.tedd.an@gmail.com>
To:     linux-bluetooth@vger.kernel.org
Cc:     Tedd Ho-Jeong An <tedd.an@intel.com>
Subject: [PATCH v6 05/12] Bluetooth: btintel: Fix the first HCI command not work with ROM device
Date:   Tue,  3 Aug 2021 21:40:25 -0700
Message-Id: <20210804044032.59729-6-hj.tedd.an@gmail.com>
In-Reply-To: <20210804044032.59729-1-hj.tedd.an@gmail.com>
References: <20210804044032.59729-1-hj.tedd.an@gmail.com>
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From: Tedd Ho-Jeong An <tedd.an@intel.com>

The some legacy ROM controllers have a bug with the first HCI command
sent to it returning number of completed commands as zero, which would
stall the command processing in the Bluetooth core.

As a workaround, send HCI Rest command first which will reset the
controller to fix the issue.

Signed-off-by: Tedd Ho-Jeong An <tedd.an@intel.com>
---
 drivers/bluetooth/btintel.c | 20 ++++++++++++++++++++
 drivers/bluetooth/btintel.h |  1 +
 drivers/bluetooth/btusb.c   |  7 ++++++-
 3 files changed, 27 insertions(+), 1 deletion(-)

diff --git a/drivers/bluetooth/btintel.c b/drivers/bluetooth/btintel.c
index a4c8329a8945..2cf3cdf8f9cb 100644
--- a/drivers/bluetooth/btintel.c
+++ b/drivers/bluetooth/btintel.c
@@ -1675,6 +1675,26 @@ static int btintel_setup_combined(struct hci_dev *hdev)
 
 	BT_DBG("%s", hdev->name);
 
+	/* The some controllers have a bug with the first HCI command sent to it
+	 * returning number of completed commands as zero. This would stall the
+	 * command processing in the Bluetooth core.
+	 *
+	 * As a workaround, send HCI Reset command first which will reset the
+	 * number of completed commands and allow normal command processing
+	 * from now on.
+	 */
+	if (btintel_test_flag(hdev, INTEL_BROKEN_INITIAL_NCMD)) {
+		skb = __hci_cmd_sync(hdev, HCI_OP_RESET, 0, NULL,
+				     HCI_INIT_TIMEOUT);
+		if (IS_ERR(skb)) {
+			bt_dev_err(hdev,
+				   "sending initial HCI reset failed (%ld)",
+				   PTR_ERR(skb));
+			return PTR_ERR(skb);
+		}
+		kfree_skb(skb);
+	}
+
 	/* Starting from TyP device, the command parameter and response are
 	 * changed even though the OCF for HCI_Intel_Read_Version command
 	 * remains same. The legacy devices can handle even if the
diff --git a/drivers/bluetooth/btintel.h b/drivers/bluetooth/btintel.h
index fb5e73ef71eb..8a49795ad5af 100644
--- a/drivers/bluetooth/btintel.h
+++ b/drivers/bluetooth/btintel.h
@@ -144,6 +144,7 @@ enum {
 	INTEL_FIRMWARE_LOADED,
 	INTEL_FIRMWARE_FAILED,
 	INTEL_BOOTING,
+	INTEL_BROKEN_INITIAL_NCMD,
 
 	__INTEL_NUM_FLAGS,
 };
diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index 53216274764a..f4b631673e89 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -61,6 +61,7 @@ static struct usb_driver btusb_driver;
 #define BTUSB_VALID_LE_STATES   0x800000
 #define BTUSB_QCA_WCN6855	0x1000000
 #define BTUSB_INTEL_NEWGEN	0x2000000
+#define BTUSB_INTEL_BROKEN_INITIAL_NCMD 0x4000000
 
 static const struct usb_device_id btusb_table[] = {
 	/* Generic Bluetooth USB device */
@@ -372,7 +373,8 @@ static const struct usb_device_id blacklist_table[] = {
 						     BTUSB_WIDEBAND_SPEECH |
 						     BTUSB_VALID_LE_STATES },
 	{ USB_DEVICE(0x8087, 0x07da), .driver_info = BTUSB_CSR },
-	{ USB_DEVICE(0x8087, 0x07dc), .driver_info = BTUSB_INTEL_COMBINED },
+	{ USB_DEVICE(0x8087, 0x07dc), .driver_info = BTUSB_INTEL_COMBINED |
+						     BTUSB_INTEL_BROKEN_INITIAL_NCMD },
 	{ USB_DEVICE(0x8087, 0x0a2a), .driver_info = BTUSB_INTEL_COMBINED },
 	{ USB_DEVICE(0x8087, 0x0a2b), .driver_info = BTUSB_INTEL_NEW |
 						     BTUSB_WIDEBAND_SPEECH },
@@ -4335,6 +4337,9 @@ static int btusb_probe(struct usb_interface *intf,
 		set_bit(HCI_QUIRK_STRICT_DUPLICATE_FILTER, &hdev->quirks);
 		set_bit(HCI_QUIRK_SIMULTANEOUS_DISCOVERY, &hdev->quirks);
 		set_bit(HCI_QUIRK_NON_PERSISTENT_DIAG, &hdev->quirks);
+
+		if (id->driver_info & BTUSB_INTEL_BROKEN_INITIAL_NCMD)
+			btintel_set_flag(hdev, INTEL_BROKEN_INITIAL_NCMD);
 	}
 
 	if (id->driver_info & BTUSB_INTEL_NEW) {
-- 
2.25.1