From: Antonio Ospite <ao2@ao2.it>
Date: Mon, 20 Apr 2015 14:32:04 +0000 (+0200)
Subject: am7xxx: add comment about detaching kernel drivers before setting configuration
X-Git-Tag: v0.1.6~29
X-Git-Url: https://git.ao2.it/libam7xxx.git/commitdiff_plain/2f9553ff3efdbd00111e90774fd90907a2e45200?hp=cd64a0277a5ca41122a343b26e4bad98b0377256

am7xxx: add comment about detaching kernel drivers before setting configuration
---

diff --git a/src/am7xxx.c b/src/am7xxx.c
index f4203e3..6595ccf 100644
--- a/src/am7xxx.c
+++ b/src/am7xxx.c
@@ -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) {