[src/trunk]: src/sys/dev/usb usb: usb_event_thread: remove delay at startup f...

[jmcneill <jmcneill%NetBSD.org@localhost>]

details:   https://anonhg.NetBSD.org/src/rev/0cae668c1e6e
branches:  trunk
changeset: 1024127:0cae668c1e6e
user:      jmcneill <jmcneill%NetBSD.org@localhost>
date:      Sun Oct 10 20:14:09 2021 +0000

description:
usb: usb_event_thread: remove delay at startup for USB >= 2.0 HCs

The delay at the start of usb_event_thread is meant to slow down EHCI
companion controllers. Skip the 500ms delay if the bus that owns this
thread is USB >= 2.0 since those are never companions.

diffstat:

 sys/dev/usb/usb.c |  8 +++++---
 1 files changed, 5 insertions(+), 3 deletions(-)

diffs (29 lines):

diff -r c888bb849bd7 -r 0cae668c1e6e sys/dev/usb/usb.c
--- a/sys/dev/usb/usb.c Sun Oct 10 20:10:12 2021 +0000
+++ b/sys/dev/usb/usb.c Sun Oct 10 20:14:09 2021 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: usb.c,v 1.197 2021/09/26 01:16:09 thorpej Exp $        */
+/*     $NetBSD: usb.c,v 1.198 2021/10/10 20:14:09 jmcneill Exp $       */
 
 /*
  * Copyright (c) 1998, 2002, 2008, 2012 The NetBSD Foundation, Inc.
@@ -37,7 +37,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: usb.c,v 1.197 2021/09/26 01:16:09 thorpej Exp $");
+__KERNEL_RCSID(0, "$NetBSD: usb.c,v 1.198 2021/10/10 20:14:09 jmcneill Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_usb.h"
@@ -724,7 +724,9 @@
         * know how to synchronize the creation of the threads so it
         * will work.
         */
-       usb_delay_ms(bus, 500);
+       if (bus->ub_revision < USBREV_2_0) {
+               usb_delay_ms(bus, 500);
+       }
 
        /* Make sure first discover does something. */
        mutex_enter(bus->ub_lock);