X-Git-Url: https://sigrok.org/gitweb/?a=blobdiff_plain;f=src%2Fdevice.c;h=537c89eff2ab353c167152de2af775a4317736a0;hb=4619fab47acf4fb0a1c035072c2e8552b4bcbae3;hp=fe3e231616e67c13989be8340cb74dcddd7195ae;hpb=c1aae90038456a61d0f9313d34e6107c3440d3e7;p=libsigrok.git

diff --git a/src/device.c b/src/device.c
index fe3e2316..537c89ef 100644
--- a/src/device.c
+++ b/src/device.c
@@ -17,9 +17,9 @@
  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  */
 
+#include <config.h>
 #include <stdio.h>
 #include <glib.h>
-#include "config.h" /* Needed for HAVE_LIBUSB_1_0 and others. */
 #include <libsigrok/libsigrok.h>
 #include "libsigrok-internal.h"
 
@@ -133,6 +133,25 @@ SR_API int sr_dev_channel_enable(struct sr_channel *channel,
 	return SR_OK;
 }
 
+/* Returns the next enabled channel, wrapping around if necessary. */
+SR_PRIV struct sr_channel *sr_next_enabled_channel(const struct sr_dev_inst *sdi,
+		struct sr_channel *cur_channel)
+{
+	struct sr_channel *next_channel;
+	GSList *l;
+
+	next_channel = cur_channel;
+	do {
+		l = g_slist_find(sdi->channels, next_channel);
+		if (l && l->next)
+			next_channel = l->next->data;
+		else
+			next_channel = sdi->channels->data;
+	} while (!next_channel->enabled);
+
+	return next_channel;
+}
+
 /**
  * Determine whether the specified device instance has the specified
  * capability.
@@ -522,11 +541,10 @@ SR_API const char *sr_dev_inst_connid_get(const struct sr_dev_inst *sdi)
 {
 #ifdef HAVE_LIBUSB_1_0
 	struct drv_context *drvc;
-	int r, cnt, i, a, b;
+	int cnt, i, a, b;
 	char connection_id[64];
 	struct sr_usb_dev_inst *usb;
 	struct libusb_device **devlist;
-	struct libusb_device_descriptor des;
 #endif
 
 	if (!sdi)
@@ -557,12 +575,6 @@ SR_API const char *sr_dev_inst_connid_get(const struct sr_dev_inst *sdi)
 		}
 
 		for (i = 0; i < cnt; i++) {
-			if ((r = libusb_get_device_descriptor(devlist[i], &des)) < 0) {
-				sr_err("Failed to get device descriptor: %s.",
-				       libusb_error_name(r));
-				continue;
-			}
-
 			/* Find the USB device by the logical address we know. */
 			b = libusb_get_bus_number(devlist[i]);
 			a = libusb_get_device_address(devlist[i]);