[src/trunk]: src/sys/dev/usb don't call usb_syncmem() for zero-length packets.

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

details:   https://anonhg.NetBSD.org/src/rev/a3878906f986
branches:  trunk
changeset: 744506:a3878906f986
user:      mrg <mrg%NetBSD.org@localhost>
date:      Tue Feb 04 06:30:46 2020 +0000

description:
don't call usb_syncmem() for zero-length packets.

diffstat:

 sys/dev/usb/ehci.c |  52 +++++++++++++++++++++++++++++++---------------------
 1 files changed, 31 insertions(+), 21 deletions(-)

diffs (127 lines):

diff -r abc547885f8a -r a3878906f986 sys/dev/usb/ehci.c
--- a/sys/dev/usb/ehci.c        Tue Feb 04 05:44:14 2020 +0000
+++ b/sys/dev/usb/ehci.c        Tue Feb 04 06:30:46 2020 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: ehci.c,v 1.268 2019/12/31 18:11:18 skrll Exp $ */
+/*     $NetBSD: ehci.c,v 1.269 2020/02/04 06:30:46 mrg Exp $ */
 
 /*
  * Copyright (c) 2004-2012 The NetBSD Foundation, Inc.
@@ -53,7 +53,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: ehci.c,v 1.268 2019/12/31 18:11:18 skrll Exp $");
+__KERNEL_RCSID(0, "$NetBSD: ehci.c,v 1.269 2020/02/04 06:30:46 mrg Exp $");
 
 #include "ohci.h"
 #include "uhci.h"
@@ -3946,8 +3946,9 @@
        DPRINTFN(5, "--- dump end ---", 0, 0, 0, 0);
 #endif
 
-       usb_syncmem(&xfer->ux_dmabuf, 0, xfer->ux_length,
-           isread ? BUS_DMASYNC_PREREAD : BUS_DMASYNC_PREWRITE);
+       if (xfer->ux_length)
+               usb_syncmem(&xfer->ux_dmabuf, 0, xfer->ux_length,
+                   isread ? BUS_DMASYNC_PREREAD : BUS_DMASYNC_PREWRITE);
 
        /* also does usb_syncmem(sqh) */
        ehci_set_qh_qtd(sqh, exfer->ex_sqtdstart);
@@ -4020,8 +4021,9 @@
 
        KASSERT(sc->sc_bus.ub_usepolling || mutex_owned(&sc->sc_lock));
 
-       usb_syncmem(&xfer->ux_dmabuf, 0, xfer->ux_length,
-           rd ? BUS_DMASYNC_POSTREAD : BUS_DMASYNC_POSTWRITE);
+       if (xfer->ux_length)
+               usb_syncmem(&xfer->ux_dmabuf, 0, xfer->ux_length,
+                   rd ? BUS_DMASYNC_POSTREAD : BUS_DMASYNC_POSTWRITE);
 
        DPRINTF("length=%jd", xfer->ux_actlen, 0, 0, 0);
 }
@@ -4163,8 +4165,9 @@
        DPRINTFN(5, "--- dump end ---", 0, 0, 0, 0);
 #endif
 
-       usb_syncmem(&xfer->ux_dmabuf, 0, xfer->ux_length,
-           isread ? BUS_DMASYNC_PREREAD : BUS_DMASYNC_PREWRITE);
+       if (xfer->ux_length)
+               usb_syncmem(&xfer->ux_dmabuf, 0, xfer->ux_length,
+                   isread ? BUS_DMASYNC_PREREAD : BUS_DMASYNC_PREWRITE);
 
        /* also does usb_syncmem(sqh) */
        ehci_set_qh_qtd(sqh, exfer->ex_sqtdstart);
@@ -4226,7 +4229,6 @@
 {
        ehci_softc_t *sc __diagused = EHCI_XFER2SC(xfer);
        struct ehci_pipe *epipe = EHCI_XFER2EPIPE(xfer);
-       int isread, endpt;
 
        EHCIHIST_FUNC(); EHCIHIST_CALLED();
 
@@ -4234,10 +4236,14 @@
 
        KASSERT(sc->sc_bus.ub_usepolling || mutex_owned(&sc->sc_lock));
 
-       endpt = epipe->pipe.up_endpoint->ue_edesc->bEndpointAddress;
-       isread = UE_GET_DIR(endpt) == UE_DIR_IN;
-       usb_syncmem(&xfer->ux_dmabuf, 0, xfer->ux_length,
-           isread ? BUS_DMASYNC_POSTREAD : BUS_DMASYNC_POSTWRITE);
+       if (xfer->ux_length) {
+               int isread, endpt;
+
+               endpt = epipe->pipe.up_endpoint->ue_edesc->bEndpointAddress;
+               isread = UE_GET_DIR(endpt) == UE_DIR_IN;
+               usb_syncmem(&xfer->ux_dmabuf, 0, xfer->ux_length,
+                   isread ? BUS_DMASYNC_POSTREAD : BUS_DMASYNC_POSTWRITE);
+       }
 }
 
 /************************/
@@ -4493,8 +4499,9 @@
            sizeof(sitd->sitd.sitd_trans),
            BUS_DMASYNC_PREWRITE | BUS_DMASYNC_PREREAD);
 
-       usb_syncmem(&exfer->ex_xfer.ux_dmabuf, 0, total_length,
-           BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
+       if (total_length)
+               usb_syncmem(&exfer->ex_xfer.ux_dmabuf, 0, total_length,
+                   BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
 
        /*
         * Part 2: Transfer descriptors have now been set up, now they must
@@ -4601,8 +4608,9 @@
        epipe->isoc.cur_xfers--;
        ehci_remove_sitd_chain(sc, exfer->ex_itdstart);
 
-       usb_syncmem(&xfer->ux_dmabuf, 0, xfer->ux_length,
-           BUS_DMASYNC_POSTWRITE | BUS_DMASYNC_POSTREAD);
+       if (xfer->ux_length)
+               usb_syncmem(&xfer->ux_dmabuf, 0, xfer->ux_length,
+                   BUS_DMASYNC_POSTWRITE | BUS_DMASYNC_POSTREAD);
 }
 
 /* -------------------------------------------------------------------------- */
@@ -4879,8 +4887,9 @@
                prev = itd;
        } /* End of frame */
 
-       usb_syncmem(&exfer->ex_xfer.ux_dmabuf, 0, total_length,
-           BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
+       if (total_length)
+               usb_syncmem(&exfer->ex_xfer.ux_dmabuf, 0, total_length,
+                   BUS_DMASYNC_PREREAD | BUS_DMASYNC_PREWRITE);
 
        /*
         * Part 2: Transfer descriptors have now been set up, now they must
@@ -4991,6 +5000,7 @@
 
        epipe->isoc.cur_xfers--;
        ehci_remove_itd_chain(sc, exfer->ex_sitdstart);
-       usb_syncmem(&xfer->ux_dmabuf, 0, xfer->ux_length,
-           BUS_DMASYNC_POSTWRITE | BUS_DMASYNC_POSTREAD);
+       if (xfer->ux_length)
+               usb_syncmem(&xfer->ux_dmabuf, 0, xfer->ux_length,
+                   BUS_DMASYNC_POSTWRITE | BUS_DMASYNC_POSTREAD);
 }