From: Uffe Jakobsen <redacted>
Date: Thu, 22 Jan 2015 00:11:22 +0000 (+0100)
Subject: Fix FreeBSD issue with libusb_get_port_numbers()
X-Git-Tag: libsigrok-0.4.0~672
X-Git-Url: https://sigrok.org/gitaction?a=commitdiff_plain;h=19643b96e27cdeb84123fc91158b25a0d1a6368d;p=libsigrok.git

Fix FreeBSD issue with libusb_get_port_numbers()

Currently (as of date 20150122) an ioctl problem within the
FreeBSD kernel is preventing libusb_get_port_numbers() from working.
Hence calls to libusb_get_port_numbers() will always return 0.
This makes it impossible to establish a physical path the the usb device.

This problem has existed "forever" -
meaning that libusb_get_port_numbers() has never worked.

A fix is committed to FreeBSD "current" head  -
and will later be merged (MFC'ed) to maintenance branches.
See: https://svnweb.freebsd.org/base?view=revision&revision=277417

Additionally FreeBSD requires that devices prior to calling
libusb_get_port_numbers() have been opened with libusb_open().

The patch is "forwards-compatible".
Currently it acts specificly to libusb_get_port_numbers()
currently returning 0 on FreeBSD.
In these situations it constructs an artificial path to the device.
When FreeBSD kernels appears with proper working ioctl
supporting libusb_get_port_numbers() the code will construct
proper physical paths for newer kernels - while still generating
artificial physical paths for older defective kernels.
---

diff --git a/src/usb.c b/src/usb.c
index 8bdb8d60..9c34b38a 100644
--- a/src/usb.c
+++ b/src/usb.c
@@ -276,8 +276,27 @@ SR_PRIV int usb_get_port_path(libusb_device *dev, char *path, int path_len)
 	uint8_t port_numbers[8];
 	int i, n, len;
 
+/*
+ * FreeBSD requires that devices prior to calling libusb_get_port_numbers()
+ * have been opened with libusb_open().
+ */
+#ifdef __FreeBSD__
+	struct libusb_device_handle *devh;
+	if (libusb_open(dev, &devh) != 0)
+		return SR_ERR;
+#endif
 	n = libusb_get_port_numbers(dev, port_numbers, sizeof(port_numbers));
+#ifdef __FreeBSD__
+	libusb_close(devh);
+#endif
 
+/* Workaround FreeBSD libusb_get_port_numbers() returning 0. */
+#ifdef __FreeBSD__
+	if (n == 0) {
+		port_numbers[0] = libusb_get_device_address(dev);
+		n = 1;
+	}
+#endif
 	if (n < 1)
 		return SR_ERR;