[src/trunk]: src/sys/dev/ic When possible, use ring mode for descriptors. No...

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

details:   https://anonhg.NetBSD.org/src/rev/0a2265208509
branches:  trunk
changeset: 481428:0a2265208509
user:      thorpej <thorpej%NetBSD.org@localhost>
date:      Fri Jan 28 23:23:49 2000 +0000

description:
When possible, use ring mode for descriptors.  Not only is this slightly
more efficient on genuine DEC chips, but some clones apparently Lose Badly
if you use chain mode.  To further complicate things, some clones *only*
do chain mode, so make this whole mess conditional.

diffstat:

 sys/dev/ic/tulip.c    |  44 ++++++++++++++++++++++++++++++++++++++------
 sys/dev/ic/tulipvar.h |   8 ++++++--
 2 files changed, 44 insertions(+), 8 deletions(-)

diffs (134 lines):

diff -r 3e5d053c83c1 -r 0a2265208509 sys/dev/ic/tulip.c
--- a/sys/dev/ic/tulip.c        Fri Jan 28 22:23:58 2000 +0000
+++ b/sys/dev/ic/tulip.c        Fri Jan 28 23:23:49 2000 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: tulip.c,v 1.40 2000/01/28 22:23:58 thorpej Exp $       */
+/*     $NetBSD: tulip.c,v 1.41 2000/01/28 23:23:49 thorpej Exp $       */
 
 /*-
  * Copyright (c) 1998, 1999, 2000 The NetBSD Foundation, Inc.
@@ -287,6 +287,15 @@
 
        /*
         * Set up various chip-specific quirks.
+        *
+        * Note that wherever we can, we use the "ring" option for
+        * transmit and receive descriptors.  This is because some
+        * clone chips apparently have problems when using chaining,
+        * although some *only* support chaining.
+        *
+        * What we do is always program the "next" pointer, and then
+        * conditionally set the TDCTL_CH and TDCTL_ER bits in the
+        * appropriate places.
         */
        switch (sc->sc_chip) {
        case TULIP_CHIP_21140:
@@ -299,11 +308,21 @@
        case TULIP_CHIP_MX98715:        /* 21143-like */
        case TULIP_CHIP_MX98715A:       /* 21143-like */
        case TULIP_CHIP_MX98725:        /* 21143-like */
+               /*
+                * Run these chips in ring mode.
+                */
+               sc->sc_tdctl_ch = 0;
+               sc->sc_tdctl_er = TDCTL_ER;
                sc->sc_preinit = tlp_2114x_preinit;
                break;
 
        case TULIP_CHIP_82C168:
        case TULIP_CHIP_82C169:
+               /*
+                * Run these chips in ring mode.
+                */
+               sc->sc_tdctl_ch = 0;
+               sc->sc_tdctl_er = TDCTL_ER;
                sc->sc_preinit = tlp_pnic_preinit;
 
                /*
@@ -314,11 +333,20 @@
                break;
 
        case TULIP_CHIP_WB89C840F:
+               /*
+                * Run this chip in chained mode.
+                */
+               sc->sc_tdctl_ch = TDCTL_CH;
+               sc->sc_tdctl_er = 0;
                sc->sc_flags |= TULIPF_IC_FS;
                break;
 
        default:
-               /* Nothing. */
+               /*
+                * Default to running in ring mode.
+                */
+               sc->sc_tdctl_ch = 0;
+               sc->sc_tdctl_er = TDCTL_ER;
        }
 
        /*
@@ -645,7 +673,9 @@
                            htole32(dmamap->dm_segs[seg].ds_addr);
                        sc->sc_txdescs[nexttx].td_ctl =
                            htole32((dmamap->dm_segs[seg].ds_len <<
-                               TDCTL_SIZE1_SHIFT) | TDCTL_CH);
+                               TDCTL_SIZE1_SHIFT) | sc->sc_tdctl_ch |
+                               (nexttx == (TULIP_NTXDESC - 1) ?
+                                sc->sc_tdctl_er : 0));
                        lasttx = nexttx;
                }
 
@@ -1543,10 +1573,11 @@
         */
        memset(sc->sc_txdescs, 0, sizeof(sc->sc_txdescs));
        for (i = 0; i < TULIP_NTXDESC; i++) {
-               sc->sc_txdescs[i].td_ctl = htole32(TDCTL_CH);
+               sc->sc_txdescs[i].td_ctl = htole32(sc->sc_tdctl_ch);
                sc->sc_txdescs[i].td_bufaddr2 =
                    htole32(TULIP_CDTXADDR(sc, TULIP_NEXTTX(i)));
        }
+       sc->sc_txdescs[TULIP_NTXDESC - 1].td_ctl |= htole32(sc->sc_tdctl_er);
        TULIP_CDTXSYNC(sc, 0, TULIP_NTXDESC,
            BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);
        sc->sc_txfree = TULIP_NTXDESC;
@@ -2388,8 +2419,9 @@
            htole32(TULIP_CDSPADDR(sc));
        sc->sc_txdescs[sc->sc_txnext].td_ctl =
            htole32((TULIP_SETUP_PACKET_LEN << TDCTL_SIZE1_SHIFT) |
-           sc->sc_filtmode | TDCTL_Tx_SET | TDCTL_Tx_FS | TDCTL_Tx_LS |
-           TDCTL_Tx_IC | TDCTL_CH);
+           sc->sc_filtmode | TDCTL_Tx_SET | TDCTL_Tx_FS |
+           TDCTL_Tx_LS | TDCTL_Tx_IC | sc->sc_tdctl_ch |
+           (sc->sc_txnext == (TULIP_NTXDESC - 1) ? sc->sc_tdctl_er : 0));
        sc->sc_txdescs[sc->sc_txnext].td_status = htole32(TDSTAT_OWN);
        TULIP_CDTXSYNC(sc, sc->sc_txnext, txs->txs_ndescs,
            BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE);
diff -r 3e5d053c83c1 -r 0a2265208509 sys/dev/ic/tulipvar.h
--- a/sys/dev/ic/tulipvar.h     Fri Jan 28 22:23:58 2000 +0000
+++ b/sys/dev/ic/tulipvar.h     Fri Jan 28 23:23:49 2000 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: tulipvar.h,v 1.26 2000/01/28 22:23:59 thorpej Exp $    */
+/*     $NetBSD: tulipvar.h,v 1.27 2000/01/28 23:23:50 thorpej Exp $    */
 
 /*-
  * Copyright (c) 1998, 1999, 2000 The NetBSD Foundation, Inc.
@@ -359,6 +359,9 @@
        int     sc_txnext;              /* next ready Tx descriptor */
        int     sc_ntxsegs;             /* number of transmit segs per pkt */
 
+       u_int32_t sc_tdctl_ch;          /* conditional desc chaining */
+       u_int32_t sc_tdctl_er;          /* conditional desc end-of-ring */
+
        struct tulip_txsq sc_txfreeq;   /* free Tx descsofts */
        struct tulip_txsq sc_txdirtyq;  /* dirty Tx descsofts */
 
@@ -446,7 +449,8 @@
            htole32(TULIP_CDRXADDR((sc), TULIP_NEXTRX((x))));           \
        __rxd->td_ctl =                                                 \
            htole32(((__m->m_ext.ext_size - 1) << TDCTL_SIZE1_SHIFT) |  \
-           TDCTL_CH);                                                  \
+           (sc)->sc_tdctl_ch |                                         \
+           ((x) == (TULIP_NRXDESC - 1) ? sc->sc_tdctl_er : 0));        \
        __rxd->td_status = htole32(TDSTAT_OWN|TDSTAT_Rx_FS|TDSTAT_Rx_LS); \
        TULIP_CDRXSYNC((sc), (x), BUS_DMASYNC_PREREAD|BUS_DMASYNC_PREWRITE); \
 } while (0)