From: Benjamin Berg <bberg@redhat.com>
Date: Tue, 1 Mar 2022 14:08:38 +0000 (+0100)
Subject: core: Suppress hotplug events during initial enumeration
X-Git-Tag: accepted/tizen/8.0/unified/20231005.095128^0
X-Git-Url: http://review.tizen.org/git/?a=commitdiff_plain;h=refs%2Fchanges%2F50%2F290950%2F1;p=platform%2Fupstream%2Flibusb.git

core: Suppress hotplug events during initial enumeration

The initial enumeration should not result in hotplug events to be fired.
This is just a convenience though, API users still need to be prepared
to be notified a second time for a device that was plugged in between
libusb_init and libusb_hotplug_register_callback.

This regressed with commit 6929b82 ("Fix segmentation fault in
libusb_init() if usbi_backend.init() fails"). This commit avoids the
mentioned segmentation fault by avoiding to clean up the hotplug code if
it was not yet initialised.

Fixes #1082
Closes #1090
References #989

[Cherrypick from mainline commit 0846456 ("core: Suppress hotplug events during initial enumeration")]
Signed-off-by: Marek Szyprowski <m.szyprowski@samsung.com>
Change-Id: Idbae2c394ba01694f9e6006d8a52036f6c73da77
---

diff --git a/libusb/core.c b/libusb/core.c
index 1c1ada1..3559470 100644
--- a/libusb/core.c
+++ b/libusb/core.c
@@ -2346,14 +2346,15 @@ int API_EXPORTED libusb_init(libusb_context **ctx)
 	list_add(&_ctx->list, &active_contexts_list);
 	usbi_mutex_static_unlock(&active_contexts_lock);
 
-	usbi_hotplug_init(_ctx);
-
 	if (usbi_backend.init) {
 		r = usbi_backend.init(_ctx);
 		if (r)
 			goto err_io_exit;
 	}
 
+	/* Initialize hotplug after the initial enumeration is done. */
+	usbi_hotplug_init(_ctx);
+
 	if (ctx)
 		*ctx = _ctx;
 
diff --git a/libusb/hotplug.c b/libusb/hotplug.c
index 402e693..6b743c7 100644
--- a/libusb/hotplug.c
+++ b/libusb/hotplug.c
@@ -171,6 +171,9 @@ void usbi_hotplug_exit(struct libusb_context *ctx)
 	if (!libusb_has_capability(LIBUSB_CAP_HAS_HOTPLUG))
 		return;
 
+	if (!usbi_atomic_load(&ctx->hotplug_ready))
+		return;
+
 	/* free all registered hotplug callbacks */
 	for_each_hotplug_cb_safe(ctx, hotplug_cb, next_cb) {
 		list_del(&hotplug_cb->list);
diff --git a/libusb/version_nano.h b/libusb/version_nano.h
index 7bf6ace..10c3ecf 100644
--- a/libusb/version_nano.h
+++ b/libusb/version_nano.h
@@ -1 +1 @@
-#define LIBUSB_NANO 11694
+#define LIBUSB_NANO 11695