USB device detach events [PATCH - please test]
Johny Mattsson
lonewolf-freebsd at earthmagic.org
Tue Oct 21 03:10:30 PDT 2003
Hello,
As an answer to my previous email, I now have patches fixing the missing
USB device detach events. This works extremely well on my system, but
it'd be great if I could get some wider exposure before I send-pr them.
From my perusal/grepping of all the usb drivers, these patches
shouldn't break anything, only allow usbd to receive DEVICE_DETACH
events for all devices.
When I continued chasing my original problem, I discovered that the
usbd_add_dev_event(USB_EVENT_DEVICE_DETACH, dev) call in usb_subr.c was
commented out. Bringing it back into play brought me a nice solid system
freeze, followed by a reboot shortly thereafter. I figure that must be
why it was commented out in the first place.
As it turns out, the placement of that call is really bad. The 'dev' it
hands out is in an inconsistent state if any subdevs existed (if there
were no subdevs, everything works fine). I say existed, because at the
original location of the "add event" call, the subdevs have already been
detached. The usbd_add_dev_event function however calls the
usbd_fill_deviceinfo, which wants to fiddle with the subdevs as well,
resulting in Bad Things happening. My patch to usb_subr.c simply moves
the usbd_add_dev_event call to just before the subdevs are disconnected.
Also, the patch to usb.c guarantees (I believe) that if a DRIVER_DETACH
event is added to the queue before the DEVICE_DETACH event has been
processed, the DEVICE_DETACH is kept on the queue, resulting in expected
behaviour by usbd.
Comments are welcome. If I don't hear anything from anyone, I'll send-pr
in a couple of days.
Cheers,
/Johny
--
Johny Mattsson - System Designer ,-. ,-. ,-. There is no truth.
http://www.earthmagic.org _.' `-' `-' There is only perception.
-------------- next part --------------
--- usb_subr.c.org Tue Oct 21 17:44:48 2003
+++ usb_subr.c Tue Oct 21 19:40:44 2003
@@ -1353,6 +1353,8 @@
}
#endif
+ usbd_add_dev_event(USB_EVENT_DEVICE_DETACH, dev);
+
if (dev->subdevs != NULL) {
DPRINTFN(3,("usb_disconnect_port: disconnect subdevs\n"));
for (i = 0; dev->subdevs[i]; i++) {
@@ -1365,7 +1367,6 @@
}
}
- /*usbd_add_dev_event(USB_EVENT_DEVICE_DETACH, dev);*/
dev->bus->devices[dev->address] = NULL;
up->device = NULL;
usb_free_device(dev);
-------------- next part --------------
--- usb.c.org Tue Oct 21 16:51:25 2003
+++ usb.c Tue Oct 21 19:42:00 2003
@@ -781,7 +781,8 @@
for (ueqi = TAILQ_FIRST(&usb_events); ueqi; ueqi = ueqi_next) {
ueqi_next = TAILQ_NEXT(ueqi, next);
if (ueqi->ue.u.ue_driver.ue_cookie.cookie ==
- uep->u.ue_device.udi_cookie.cookie) {
+ uep->u.ue_device.udi_cookie.cookie &&
+ !USB_EVENT_IS_DETACH(ueqi->ue.ue_type)) {
TAILQ_REMOVE(&usb_events, ueqi, next);
free(ueqi, M_USBDEV);
usb_nevents--;
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