laforge has uploaded this change for review.
osmo_libusb: Use libusb_get_pollfds() to get initial file descriptors
It seems it is insufficient to register file-descriptor call-backs
with libusb_set_pollfd_notifiers(), but we also need to call
libusb_get_pollfds() once to get the initial set of file descriptors
which may have been created already during libusb_init().
As we don't have a libusb context before libusb_init() returns,
we cannot call libusb_set_pollfd_notifiers() early enough to be
active already during libusb_init().
Change-Id: Icf81014d689ffa738719af68120fa2dedbeec689
---
M src/usb/osmo_libusb.c
1 file changed, 13 insertions(+), 0 deletions(-)
git pull ssh://gerrit.osmocom.org:29418/libosmocore refs/changes/38/27038/1
diff --git a/src/usb/osmo_libusb.c b/src/usb/osmo_libusb.c
index a6f194a..79a8fc3 100644
--- a/src/usb/osmo_libusb.c
+++ b/src/usb/osmo_libusb.c
@@ -735,6 +735,8 @@
int osmo_libusb_init(libusb_context **pluctx)
{
libusb_context *luctx = NULL;
+ const struct libusb_pollfd **pfds;
+
int rc;
rc = libusb_init(pluctx);
@@ -750,6 +752,17 @@
libusb_set_pollfd_notifiers(luctx, osmo_usb_added_cb, osmo_usb_removed_cb, luctx);
+ /* get the initial file descriptors which were created even before during libusb_init() */
+ pfds = libusb_get_pollfds(luctx);
+ if (pfds) {
+ const struct libusb_pollfd **pfds2 = pfds;
+ const struct libusb_pollfd *pfd;
+ /* synthesize 'add' call-backs. not sure why libusb doesn't do that by itself? */
+ for (pfd = *pfds2; pfd; pfd = *++pfds2)
+ osmo_usb_added_cb(pfd->fd, pfd->events, luctx);
+ libusb_free_pollfds(pfds);
+ }
+
return 0;
}
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