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From:   Luiz Augusto von Dentz <luiz.dentz@gmail.com>
To:     linux-bluetooth@vger.kernel.org
Subject: [PATCH v10 2/9] Bluetooth: btintel: Move operational checks after version check
Date:   Tue, 23 Mar 2021 11:58:57 -0700
Message-Id: <20210323185904.3372987-2-luiz.dentz@gmail.com>
In-Reply-To: <20210323185904.3372987-1-luiz.dentz@gmail.com>
References: <20210323185904.3372987-1-luiz.dentz@gmail.com>
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From: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>

In order to allow new firmware to load, it first needs to check if the
firmware version on file matches the one loaded if it doesn't, then it
needs to revert to bootloader mode in order to load the new firmware.

Signed-off-by: Luiz Augusto von Dentz <luiz.von.dentz@intel.com>
---
 drivers/bluetooth/btintel.c | 22 ++++++++++++
 drivers/bluetooth/btusb.c   | 68 +++++++++++++------------------------
 2 files changed, 46 insertions(+), 44 deletions(-)

diff --git a/drivers/bluetooth/btintel.c b/drivers/bluetooth/btintel.c
index 3ff698a0bd25..13bc93a986c7 100644
--- a/drivers/bluetooth/btintel.c
+++ b/drivers/bluetooth/btintel.c
@@ -958,6 +958,17 @@ int btintel_download_firmware(struct hci_dev *hdev,
 		}
 	}
 
+	/* The firmware variant determines if the device is in bootloader
+	 * mode or is running operational firmware. The value 0x06 identifies
+	 * the bootloader and the value 0x23 identifies the operational
+	 * firmware.
+	 *
+	 * If the firmware version has changed that means it needs to be reset
+	 * to bootloader when operational so the new firmware can be loaded.
+	 */
+	if (ver->fw_variant == 0x23)
+		return -EINVAL;
+
 	err = btintel_sfi_rsa_header_secure_send(hdev, fw);
 	if (err)
 		return err;
@@ -985,6 +996,17 @@ int btintel_download_firmware_newgen(struct hci_dev *hdev,
 		return -EALREADY;
 	}
 
+	/* The firmware variant determines if the device is in bootloader
+	 * mode or is running operational firmware. The value 0x01 identifies
+	 * the bootloader and the value 0x03 identifies the operational
+	 * firmware.
+	 *
+	 * If the firmware version has changed that means it needs to be reset
+	 * to bootloader when operational so the new firmware can be loaded.
+	 */
+	if (ver->img_type == 0x03)
+		return -EINVAL;
+
 	/* iBT hardware variants 0x0b, 0x0c, 0x11, 0x12, 0x13, 0x14 support
 	 * only RSA secure boot engine. Hence, the corresponding sfi file will
 	 * have RSA header of 644 bytes followed by Command Buffer.
diff --git a/drivers/bluetooth/btusb.c b/drivers/bluetooth/btusb.c
index de220ab7f231..a30f7ea9be36 100644
--- a/drivers/bluetooth/btusb.c
+++ b/drivers/bluetooth/btusb.c
@@ -2402,11 +2402,17 @@ static int btusb_send_frame_intel(struct hci_dev *hdev, struct sk_buff *skb)
 	return -EILSEQ;
 }
 
-static bool btusb_setup_intel_new_get_fw_name(struct intel_version *ver,
+static int btusb_setup_intel_new_get_fw_name(struct intel_version *ver,
 					     struct intel_boot_params *params,
 					     char *fw_name, size_t len,
 					     const char *suffix)
 {
+	/* The hardware platform number has a fixed value of 0x37 and
+	 * for now only accept this single value.
+	 */
+	if (ver->hw_platform != 0x37)
+		return -EINVAL;
+
 	switch (ver->hw_variant) {
 	case 0x0b:	/* SfP */
 	case 0x0c:	/* WsP */
@@ -2426,9 +2432,10 @@ static bool btusb_setup_intel_new_get_fw_name(struct intel_version *ver,
 			suffix);
 		break;
 	default:
-		return false;
+		return -EINVAL;
 	}
-	return true;
+
+	return 0;
 }
 
 static void btusb_setup_intel_newgen_get_fw_name(const struct intel_version_tlv *ver_tlv,
@@ -2483,7 +2490,6 @@ static int btusb_intel_download_firmware_newgen(struct hci_dev *hdev,
 	if (ver->img_type == 0x03) {
 		clear_bit(BTUSB_BOOTLOADER, &data->flags);
 		btintel_check_bdaddr(hdev);
-		return 0;
 	}
 
 	/* Check for supported iBT hardware variants of this firmware
@@ -2628,35 +2634,6 @@ static int btusb_intel_download_firmware(struct hci_dev *hdev,
 	if (!ver || !params)
 		return -EINVAL;
 
-	/* The hardware platform number has a fixed value of 0x37 and
-	 * for now only accept this single value.
-	 */
-	if (ver->hw_platform != 0x37) {
-		bt_dev_err(hdev, "Unsupported Intel hardware platform (%u)",
-			   ver->hw_platform);
-		return -EINVAL;
-	}
-
-	/* Check for supported iBT hardware variants of this firmware
-	 * loading method.
-	 *
-	 * This check has been put in place to ensure correct forward
-	 * compatibility options when newer hardware variants come along.
-	 */
-	switch (ver->hw_variant) {
-	case 0x0b:	/* SfP */
-	case 0x0c:	/* WsP */
-	case 0x11:	/* JfP */
-	case 0x12:	/* ThP */
-	case 0x13:	/* HrP */
-	case 0x14:	/* CcP */
-		break;
-	default:
-		bt_dev_err(hdev, "Unsupported Intel hardware variant (%u)",
-			   ver->hw_variant);
-		return -EINVAL;
-	}
-
 	btintel_version_info(hdev, ver);
 
 	/* The firmware variant determines if the device is in bootloader
@@ -2675,16 +2652,18 @@ static int btusb_intel_download_firmware(struct hci_dev *hdev,
 	if (ver->fw_variant == 0x23) {
 		clear_bit(BTUSB_BOOTLOADER, &data->flags);
 		btintel_check_bdaddr(hdev);
-		return 0;
-	}
 
-	/* If the device is not in bootloader mode, then the only possible
-	 * choice is to return an error and abort the device initialization.
-	 */
-	if (ver->fw_variant != 0x06) {
-		bt_dev_err(hdev, "Unsupported Intel firmware variant (%u)",
-			   ver->fw_variant);
-		return -ENODEV;
+		/* SfP and WsP don't seem to update the firmware version on file
+		 * so version checking is currently possible.
+		 */
+		switch (ver->hw_variant) {
+		case 0x0b:	/* SfP */
+		case 0x0c:	/* WsP */
+			return 0;
+		}
+
+		/* Proceed to download to check if the version matches */
+		goto download;
 	}
 
 	/* Read the secure boot parameters to identify the operating
@@ -2712,6 +2691,7 @@ static int btusb_intel_download_firmware(struct hci_dev *hdev,
 		set_bit(HCI_QUIRK_INVALID_BDADDR, &hdev->quirks);
 	}
 
+download:
 	/* With this Intel bootloader only the hardware variant and device
 	 * revision information are used to select the right firmware for SfP
 	 * and WsP.
@@ -2735,7 +2715,7 @@ static int btusb_intel_download_firmware(struct hci_dev *hdev,
 	 */
 	err = btusb_setup_intel_new_get_fw_name(ver, params, fwname,
 						sizeof(fwname), "sfi");
-	if (!err) {
+	if (err < 0) {
 		bt_dev_err(hdev, "Unsupported Intel firmware naming");
 		return -EINVAL;
 	}
@@ -2908,7 +2888,7 @@ static int btusb_setup_intel_new(struct hci_dev *hdev)
 	err = btusb_setup_intel_new_get_fw_name(&ver, &params, ddcname,
 						sizeof(ddcname), "ddc");
 
-	if (!err) {
+	if (err < 0) {
 		bt_dev_err(hdev, "Unsupported Intel firmware naming");
 	} else {
 		/* Once the device is running in operational mode, it needs to
-- 
2.30.2