Implement new libusb v2.0 API function, libusb20_dev_get_stats().

This function is useful when debugging USB device issues.

MFC after:	1 week
Sponsored by:	Mellanox Technologies

lib/libusb/Makefile

@@ -219,6 +219,7 @@ MLINKS += libusb20.3 libusb20_dev_get_backend_name.3
 MLINKS += libusb20.3 libusb20_dev_get_info.3
 MLINKS += libusb20.3 libusb20_dev_get_iface_desc.3
 MLINKS += libusb20.3 libusb20_dev_get_desc.3
+MLINKS += libusb20.3 libusb20_dev_get_stats.3
 MLINKS += libusb20.3 libusb20_dev_close.3
 MLINKS += libusb20.3 libusb20_dev_detach_kernel_driver.3
 MLINKS += libusb20.3 libusb20_dev_set_config_index.3

lib/libusb/libusb20.3

@@ -1,5 +1,5 @@
 .\"
-.\" Copyright (c) 2008 Hans Petter Selasky
+.\" Copyright (c) 2008-2019 Hans Petter Selasky
 .\"
 .\" All rights reserved.
 .\"
@@ -26,7 +26,7 @@
 .\"
 .\" $FreeBSD$
 .\"
-.Dd May 3, 2013
+.Dd December 27, 2019
 .Dt LIBUSB20 3
 .Os
 .Sh NAME
@@ -122,6 +122,8 @@ USB access library (libusb -lusb)
 .Ft const char *
 .Fn libusb20_dev_get_desc "struct libusb20_device *pdev"
 .Ft int
+.Fn libusb20_dev_get_stats "struct libusb20_device *pdev" "struct libusb20_device_stats *pstats"
+.Ft int
 .Fn libusb20_dev_close "struct libusb20_device *pdev"
 .Ft int
 .Fn libusb20_dev_detach_kernel_driver "struct libusb20_device *pdev" "uint8_t iface_index"
@@ -597,6 +599,14 @@ The format of the string is: "drivername<unit>: <description>"
 .
 .Pp
 .
+.Fn libusb20_dev_get_stats
+retrieves the device statistics into the structure pointed to by the
+.Fa pstats
+argument.
+This function returns zero on success else a LIBUSB20_ERROR value is returned.
+.
+.Pp
+.
 .Fn libusb20_dev_close
 will close the given USB device.
 .

lib/libusb/libusb20.c

@@ -78,6 +78,7 @@ dummy_callback(struct libusb20_transfer *xfer)
 #define	dummy_set_power_mode (void *)dummy_int
 #define	dummy_get_power_mode (void *)dummy_int
 #define	dummy_get_power_usage (void *)dummy_int
+#define	dummy_get_stats (void *)dummy_int
 #define	dummy_kernel_driver_active (void *)dummy_int
 #define	dummy_detach_kernel_driver (void *)dummy_int
 #define	dummy_do_request_sync (void *)dummy_int
@@ -1049,6 +1050,31 @@ libusb20_dev_get_speed(struct libusb20_device *pdev)
 	return (pdev->usb_speed);
 }
 
+int
+libusb20_dev_get_stats(struct libusb20_device *pdev, struct libusb20_device_stats *pstats)
+{
+	uint8_t do_close;
+	int error;
+
+	if (!pdev->is_opened) {
+		error = libusb20_dev_open(pdev, 0);
+		if (error == 0) {
+			do_close = 1;
+		} else {
+			do_close = 0;
+		}
+	} else {
+		do_close = 0;
+	}
+
+	error = pdev->methods->get_stats(pdev, pstats);
+
+	if (do_close)
+		(void) libusb20_dev_close(pdev);
+
+	return (error);
+}
+
 /* if this function returns an error, the device is gone */
 int
 libusb20_dev_process(struct libusb20_device *pdev)

lib/libusb/libusb20.h

@@ -195,6 +195,12 @@ struct libusb20_quirk {
 	char	quirkname[64 - 12];
 };
 
+struct libusb20_device_stats {
+	uint64_t xfer_ok[4];		/* sorted by USB transfer type, UE_XXX */
+	uint64_t xfer_fail[4];		/* sorted by USB transfer type, UE_XXX */
+	uint64_t xfer_reserved[24];	/* reserved */
+};
+
 #define	LIBUSB20_MAX_FRAME_PRE_SCALE	(1U << 31)
 
 /* USB transfer operations */
@@ -243,6 +249,7 @@ int	libusb20_dev_detach_kernel_driver(struct libusb20_device *pdev, uint8_t ifac
 int	libusb20_dev_set_config_index(struct libusb20_device *pdev, uint8_t configIndex);
 int	libusb20_dev_get_debug(struct libusb20_device *pdev);
 int	libusb20_dev_get_fd(struct libusb20_device *pdev);
+int	libusb20_dev_get_stats(struct libusb20_device *pdev, struct libusb20_device_stats *pstat);
 int	libusb20_dev_kernel_driver_active(struct libusb20_device *pdev, uint8_t iface_index);
 int	libusb20_dev_open(struct libusb20_device *pdev, uint16_t transfer_max);
 int	libusb20_dev_process(struct libusb20_device *pdev);

lib/libusb/libusb20_int.h

@@ -108,10 +108,12 @@ typedef int (libusb20_reset_device_t)(struct libusb20_device *pdev);
 typedef int (libusb20_set_power_mode_t)(struct libusb20_device *pdev, uint8_t power_mode);
 typedef int (libusb20_get_power_mode_t)(struct libusb20_device *pdev, uint8_t *power_mode);
 typedef int (libusb20_get_power_usage_t)(struct libusb20_device *pdev, uint16_t *power_usage);
+typedef int (libusb20_get_stats_t)(struct libusb20_device *pdev, struct libusb20_device_stats *pstats);
 typedef int (libusb20_set_alt_index_t)(struct libusb20_device *pdev, uint8_t iface_index, uint8_t alt_index);
 typedef int (libusb20_set_config_index_t)(struct libusb20_device *pdev, uint8_t index);
 typedef int (libusb20_check_connected_t)(struct libusb20_device *pdev);
 
+
 /* USB transfer specific */
 typedef int (libusb20_tr_open_t)(struct libusb20_transfer *xfer, uint32_t MaxBufSize, uint32_t MaxFrameCount, uint8_t ep_no, uint16_t stream_id, uint8_t pre_scale);
 typedef int (libusb20_tr_close_t)(struct libusb20_transfer *xfer);
@@ -131,6 +133,7 @@ typedef void (libusb20_tr_cancel_async_t)(struct libusb20_transfer *xfer);
   m(n, set_power_mode) \
   m(n, get_power_mode) \
   m(n, get_power_usage) \
+  m(n, get_stats) \
   m(n, set_alt_index) \
   m(n, set_config_index) \
   m(n, tr_cancel_async) \

lib/libusb/libusb20_ugen20.c

@@ -80,6 +80,7 @@ static libusb20_check_connected_t ugen20_check_connected;
 static libusb20_set_power_mode_t ugen20_set_power_mode;
 static libusb20_get_power_mode_t ugen20_get_power_mode;
 static libusb20_get_power_usage_t ugen20_get_power_usage;
+static libusb20_get_stats_t ugen20_get_stats;
 static libusb20_kernel_driver_active_t ugen20_kernel_driver_active;
 static libusb20_detach_kernel_driver_t ugen20_detach_kernel_driver;
 static libusb20_do_request_sync_t ugen20_do_request_sync;
@@ -669,6 +670,29 @@ ugen20_get_power_usage(struct libusb20_device *pdev, uint16_t *power_usage)
 	return (0);			/* success */
 }
 
+static int
+ugen20_get_stats(struct libusb20_device *pdev, struct libusb20_device_stats *pstats)
+{
+	struct usb_device_stats st;
+
+	if (ioctl(pdev->file_ctrl, IOUSB(USB_DEVICESTATS), &st))
+		return (LIBUSB20_ERROR_OTHER);
+
+	memset(pstats, 0, sizeof(*pstats));
+
+	pstats->xfer_ok[0] = st.uds_requests_ok[0];
+	pstats->xfer_ok[1] = st.uds_requests_ok[1];
+	pstats->xfer_ok[2] = st.uds_requests_ok[2];
+	pstats->xfer_ok[3] = st.uds_requests_ok[3];
+
+	pstats->xfer_fail[0] = st.uds_requests_fail[0];
+	pstats->xfer_fail[1] = st.uds_requests_fail[1];
+	pstats->xfer_fail[2] = st.uds_requests_fail[2];
+	pstats->xfer_fail[3] = st.uds_requests_fail[3];
+
+	return (0);			/* success */
+}
+
 static int
 ugen20_kernel_driver_active(struct libusb20_device *pdev,
     uint8_t iface_index)