Activate the kthread mechanism for doing usb bus discovery. This means

that device add/remove will work without usbd running.  usbd is still
used for execing stuff, but that is all now.  Ideally it could be replaced
by a devd some day.  Until now, usbd had to be running so that the
USB_DISCOVER ioctl could be called to walk the tree when an attachment
status change was noticed.

Among the changes:
- when a detach happens, remove any pending 'attach' messages or the system
suffers from whiplash from exec moused / kill moused loops if you do lots
of attach/detach and later start usbd.
- tweaks related to kthread differences
- disable the select handler for the old interface (never return success).
I have not removed it yet or old usbd's will abort.  That can get removed
later once usbd is cleaned up and things have stabilized for a few weeks.
- get Giant in the kthread.
- a couple of minor potential bug fixes (usb_nevents vs malloc failure etc)

Pre-approved by: n_hibma (ages and ages ago)

1 files changed, 2 insertions, 3 deletions

diff --git a/sys/dev/usb/usb_port.h b/sys/dev/usb/usb_port.h
index c7a705b..3045615 100644
--- a/sys/dev/usb/usb_port.h
+++ b/sys/dev/usb/usb_port.h
@@ -290,9 +290,8 @@ __CONCAT(dname,_detach)(self, flags) \
 #define	memcpy(d, s, l)		bcopy((s),(d),(l))
 #define	memset(d, v, l)		bzero((d),(l))
 #define bswap32(x)		swap32(x)
-#define kthread_create1(function, sc, priv, string, name)
-#define kthread_create(create_function, sc)
-#define kthread_exit(err)
+#define kthread_create1(f, s, p, a0, a1) \
+		kthread_create((f), (s), (p), RFHIGHPID, (a0), (a1))
 
 #define usb_timeout(f, d, t, h) ((h) = timeout((f), (d), (t)))
 #define usb_untimeout(f, d, h) untimeout((f), (d), (h))