1 files changed, 51 insertions, 2 deletions

diff --git a/drivers/hid/hid-logitech-hidpp.c b/drivers/hid/hid-logitech-hidpp.c
index 504e8917b..5b6bb24df 100644
--- a/drivers/hid/hid-logitech-hidpp.c
+++ b/drivers/hid/hid-logitech-hidpp.c
@@ -675,8 +675,7 @@ static int hidpp_unifying_init(struct hidpp_device *hidpp)
 	if (ret)
 		return ret;
 
-	snprintf(hdev->uniq, sizeof(hdev->uniq), "%04x-%4phD",
-		 hdev->product, &serial);
+	snprintf(hdev->uniq, sizeof(hdev->uniq), "%4phD", &serial);
 	dbg_hid("HID++ Unifying: Got serial: %s\n", hdev->uniq);
 
 	name = hidpp_unifying_get_name(hidpp);
@@ -778,6 +777,54 @@ static bool hidpp_is_connected(struct hidpp_device *hidpp)
 }
 
 /* -------------------------------------------------------------------------- */
+/* 0x0003: Device Information                                                 */
+/* -------------------------------------------------------------------------- */
+
+#define HIDPP_PAGE_DEVICE_INFORMATION			0x0003
+
+#define CMD_GET_DEVICE_INFO				0x00
+
+static int hidpp_get_serial(struct hidpp_device *hidpp, u32 *serial)
+{
+	struct hidpp_report response;
+	u8 feature_type;
+	u8 feature_index;
+	int ret;
+
+	ret = hidpp_root_get_feature(hidpp, HIDPP_PAGE_DEVICE_INFORMATION,
+				     &feature_index,
+				     &feature_type);
+	if (ret)
+		return ret;
+
+	ret = hidpp_send_fap_command_sync(hidpp, feature_index,
+					  CMD_GET_DEVICE_INFO,
+					  NULL, 0, &response);
+	if (ret)
+		return ret;
+
+	/* See hidpp_unifying_get_serial() */
+	*serial = *((u32 *)&response.rap.params[1]);
+	return 0;
+}
+
+static int hidpp_serial_init(struct hidpp_device *hidpp)
+{
+	struct hid_device *hdev = hidpp->hid_dev;
+	u32 serial;
+	int ret;
+
+	ret = hidpp_get_serial(hidpp, &serial);
+	if (ret)
+		return ret;
+
+	snprintf(hdev->uniq, sizeof(hdev->uniq), "%4phD", &serial);
+	dbg_hid("HID++ DeviceInformation: Got serial: %s\n", hdev->uniq);
+
+	return 0;
+}
+
+/* -------------------------------------------------------------------------- */
 /* 0x0005: GetDeviceNameType                                                  */
 /* -------------------------------------------------------------------------- */
 
@@ -3040,6 +3087,8 @@ static int hidpp_probe(struct hid_device *hdev, const struct hid_device_id *id)
 
 	if (hidpp->quirks & HIDPP_QUIRK_UNIFYING)
 		hidpp_unifying_init(hidpp);
+	else if (hid_is_usb(hidpp->hid_dev))
+		hidpp_serial_init(hidpp);
 
 	connected = hidpp_is_connected(hidpp);
 	atomic_set(&hidpp->connected, connected);