[src/trunk]: src/sys/dev/usb make typing on the console work during boot:

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

details:   https://anonhg.NetBSD.org/src/rev/76874deac058
branches:  trunk
changeset: 320707:76874deac058
user:      christos <christos%NetBSD.org@localhost>
date:      Mon Jul 16 23:07:31 2018 +0000

description:
make typing on the console work during boot:
1. if polling avoid mutex
2. convert spin mutex calls to regular calls in xhci_poll so that we don't
   spinout while waiting for the user to type.
Tested by phil@

diffstat:

 sys/dev/usb/xhci.c |  17 ++++++++++-------
 1 files changed, 10 insertions(+), 7 deletions(-)

diffs (60 lines):

diff -r 0e3f255da255 -r 76874deac058 sys/dev/usb/xhci.c
--- a/sys/dev/usb/xhci.c        Mon Jul 16 14:14:37 2018 +0000
+++ b/sys/dev/usb/xhci.c        Mon Jul 16 23:07:31 2018 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: xhci.c,v 1.93 2018/06/29 17:48:24 msaitoh Exp $        */
+/*     $NetBSD: xhci.c,v 1.94 2018/07/16 23:07:31 christos Exp $       */
 
 /*
  * Copyright (c) 2013 Jonathan A. Kollasch
@@ -34,7 +34,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: xhci.c,v 1.93 2018/06/29 17:48:24 msaitoh Exp $");
+__KERNEL_RCSID(0, "$NetBSD: xhci.c,v 1.94 2018/07/16 23:07:31 christos Exp $");
 
 #ifdef _KERNEL_OPT
 #include "opt_usb.h"
@@ -2175,12 +2175,12 @@
 
        XHCIHIST_FUNC(); XHCIHIST_CALLED();
 
-       mutex_spin_enter(&sc->sc_intr_lock);
+       mutex_enter(&sc->sc_intr_lock);
        int ret = xhci_intr1(sc);
        if (ret) {
                xhci_softintr(bus);
        }
-       mutex_spin_exit(&sc->sc_intr_lock);
+       mutex_exit(&sc->sc_intr_lock);
 
        return;
 }
@@ -3983,6 +3983,7 @@
        struct xhci_ring * const tr = &xs->xs_ep[dci].xe_tr;
        struct xhci_xfer * const xx = XHCI_XFER2XXFER(xfer);
        const uint32_t len = xfer->ux_length;
+       const bool polling = xhci_polling_p(sc);
        usb_dma_t * const dma = &xfer->ux_dmabuf;
        uint64_t parameter;
        uint32_t status;
@@ -4009,13 +4010,15 @@
            XHCI_TRB_3_IOC_BIT;
        xhci_trb_put(&xx->xx_trb[i++], parameter, status, control);
 
-       mutex_enter(&tr->xr_lock);
+       if (!polling)
+               mutex_enter(&tr->xr_lock);
        xhci_ring_put(sc, tr, xfer, xx->xx_trb, i);
-       mutex_exit(&tr->xr_lock);
+       if (!polling)
+               mutex_exit(&tr->xr_lock);
 
        xhci_db_write_4(sc, XHCI_DOORBELL(xs->xs_idx), dci);
 
-       if (xfer->ux_timeout && !xhci_polling_p(sc)) {
+       if (xfer->ux_timeout && !polling) {
                callout_reset(&xfer->ux_callout, mstohz(xfer->ux_timeout),
                    xhci_timeout, xfer);
        }