Produce more accurate error messages.

diff --git a/src/am7xxx.c b/src/am7xxx.c
index 5b98b84..d6615ba 100644 (file)
--- a/src/am7xxx.c
+++ b/src/am7xxx.c
@@ -310,7 +310,10 @@ static int read_data(am7xxx_device *dev, uint8_t *buffer, unsigned int len)
        int transferred = 0;
 
        ret = libusb_bulk_transfer(dev->usb_device, 0x81, buffer, len, &transferred, 0);
-       if (ret != 0 || (unsigned int)transferred != len) {
+       if (ret < 0) {
+               error(dev->ctx, "USB bulk transfer failed (%s)\n", libusb_error_name(ret));
+               return ret;
+       } else if (ret != 0 || (unsigned int)transferred != len) {
                error(dev->ctx, "ret: %d\ttransferred: %d (expected %u)\n",
                      ret, transferred, len);
                return ret;
@@ -329,7 +332,10 @@ static int send_data(am7xxx_device *dev, uint8_t *buffer, unsigned int len)
        trace_dump_buffer(dev->ctx, "sending -->", buffer, len);
 
        ret = libusb_bulk_transfer(dev->usb_device, 0x1, buffer, len, &transferred, 0);
-       if (ret != 0 || (unsigned int)transferred != len) {
+       if (ret < 0) {
+               error(dev->ctx, "USB bulk transfer failed (%s)\n", libusb_error_name(ret));
+               return ret;
+       } else if (ret != 0 || (unsigned int)transferred != len) {
                error(dev->ctx, "ret: %d\ttransferred: %d (expected %u)\n",
                      ret, transferred, len);
                return ret;
@@ -527,6 +533,7 @@ static int scan_devices(am7xxx_context *ctx, scan_op op,
 
        num_devices = libusb_get_device_list(ctx->usb_context, &list);
        if (num_devices < 0) {
+               error(ctx, "USB get device list failed (%s)\n", libusb_error_name(num_devices));
                ret = -ENODEV;
                goto out;
        }
@@ -537,8 +544,10 @@ static int scan_devices(am7xxx_context *ctx, scan_op op,
                unsigned int j;
 
                ret = libusb_get_device_descriptor(list[i], &desc);
-               if (ret < 0)
+               if (ret < 0) {
+                       debug(ctx, "USB get device descriptor failed (%s)\n", libusb_error_name(ret));
                        continue;
+               }
 
                for (j = 0; j < ARRAY_SIZE(supported_devices); j++) {
                        if (desc.idVendor == supported_devices[j].vendor_id
@@ -578,7 +587,7 @@ static int scan_devices(am7xxx_context *ctx, scan_op op,
 
                                        ret = libusb_open(list[i], &((*dev)->usb_device));
                                        if (ret < 0) {
-                                               debug(ctx, "libusb_open failed\n");
+                                               debug(ctx, "libusb_open failed (%s)\n", libusb_error_name(ret));
                                                goto out;
                                        }
 
@@ -623,8 +632,10 @@ AM7XXX_PUBLIC int am7xxx_init(am7xxx_context **ctx)
        (*ctx)->log_level = AM7XXX_LOG_TRACE;
 
        ret = libusb_init(&((*ctx)->usb_context));
-       if (ret < 0)
+       if (ret < 0) {
+               fatal("USB initialization failed (%s)\n", libusb_error_name(ret));
                goto out_free_context;
+       }
 
        libusb_set_debug((*ctx)->usb_context, 3);