Bluetooth: btbcm: Stop using upper nibble of rev to chose between uart/USB paths

btbcm_setup_patchram() was using the upper nibble of the revision code to
determine if we are dealing with an uart or USB connected bcm-bt device,
but just as btbcm_initialize() has started accepting 1 and 2 as uart
connected devices, I've now encountered an USB connected device (0a5c:216c)
which has 0 in the upper nibble. So it seems that the upper nibble is not
really a reliable indicator of the bus type.

Instead check hdev->bus which does give us a reliable indication. This
fixes the patchram code trying to load the patchram by the fallback BCM.hcd
filename, now it correctly requests BCM43142A0-0a5c-216c.hcd.

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Signed-off-by: Marcel Holtmann <marcel@holtmann.org>

drivers/bluetooth/btbcm.c

@@ -465,9 +465,11 @@ int btbcm_setup_patchram(struct hci_dev *hdev)
 	if (err)
 		return err;
 
-	switch ((rev & 0xf000) >> 12) {
+	/* Upper nibble of rev should be between 0 and 3? */
-	case 0:
+	if (((rev & 0xf000) >> 12) > 3)
-	case 3:
+		return 0;
+
+	if (hdev->bus != HCI_USB) {
 		for (i = 0; bcm_uart_subver_table[i].name; i++) {
 			if (subver == bcm_uart_subver_table[i].subver) {
 				hw_name = bcm_uart_subver_table[i].name;
@@ -477,9 +479,7 @@ int btbcm_setup_patchram(struct hci_dev *hdev)
 
 		snprintf(fw_name, sizeof(fw_name), "brcm/%s.hcd",
 			 hw_name ? : "BCM");
-		break;
+	} else {
-	case 1:
-	case 2:
 		/* Read USB Product Info */
 		skb = btbcm_read_usb_product(hdev);
 		if (IS_ERR(skb))
@@ -498,9 +498,6 @@ int btbcm_setup_patchram(struct hci_dev *hdev)
 
 		snprintf(fw_name, sizeof(fw_name), "brcm/%s-%4.4x-%4.4x.hcd",
 			 hw_name ? : "BCM", vid, pid);
-		break;
-	default:
-		return 0;
 	}
 
 	bt_dev_info(hdev, "%s (%3.3u.%3.3u.%3.3u) build %4.4u",