am7xxx: add comment about detaching kernel drivers before setting configuration
authorAntonio Ospite <ao2@ao2.it>
Mon, 20 Apr 2015 14:32:04 +0000 (16:32 +0200)
committerAntonio Ospite <ao2@ao2.it>
Mon, 20 Apr 2015 16:03:54 +0000 (18:03 +0200)
src/am7xxx.c

index f4203e3..6595ccf 100644 (file)
@@ -736,6 +736,15 @@ static int open_device(am7xxx_context *ctx,
        current_configuration = -1;
        libusb_get_configuration((*dev)->usb_device, &current_configuration);
        if (current_configuration != (*dev)->desc->configuration) {
+               /*
+                * In principle kernel drivers bound to each interface should
+                * be detached before setting the configuration, but in
+                * practice this is not necessary for most devices.
+                *
+                * For example something like the following function would be
+                * called:
+                *      libusb_detach_all_kernel_drivers((*dev)->usb_device);
+                */
                ret = libusb_set_configuration((*dev)->usb_device,
                                               (*dev)->desc->configuration);
                if (ret < 0) {