[src/trunk]: src/sys/dev/pci when doing host blits, let the fifo drain every ...

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

details:   https://anonhg.NetBSD.org/src/rev/8a2b04e07516
branches:  trunk
changeset: 777865:8a2b04e07516
user:      macallan <macallan%NetBSD.org@localhost>
date:      Thu Mar 08 05:42:44 2012 +0000

description:
when doing host blits, let the fifo drain every now and then. Apparently even
a relatively slow CPU can overload a relatively fast Rage 128 in some
circumstances.
This cures weird artifacts seen when scrolling lots and lots of text very
fast. Why this only showed up with glyph cacheing which should reduce the
frequency of host blits isn't quite clear though.

diffstat:

 sys/dev/pci/r128fb.c |  18 +++++++++++++-----
 1 files changed, 13 insertions(+), 5 deletions(-)

diffs (61 lines):

diff -r 015a5db122c8 -r 8a2b04e07516 sys/dev/pci/r128fb.c
--- a/sys/dev/pci/r128fb.c      Wed Mar 07 23:31:44 2012 +0000
+++ b/sys/dev/pci/r128fb.c      Thu Mar 08 05:42:44 2012 +0000
@@ -1,4 +1,4 @@
-/*     $NetBSD: r128fb.c,v 1.30 2012/02/16 20:45:21 macallan Exp $     */
+/*     $NetBSD: r128fb.c,v 1.31 2012/03/08 05:42:44 macallan Exp $     */
 
 /*
  * Copyright (c) 2007 Michael Lorenz
@@ -31,7 +31,7 @@
  */
 
 #include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: r128fb.c,v 1.30 2012/02/16 20:45:21 macallan Exp $");
+__KERNEL_RCSID(0, "$NetBSD: r128fb.c,v 1.31 2012/03/08 05:42:44 macallan Exp $");
 
 #include <sys/param.h>
 #include <sys/systm.h>
@@ -325,9 +325,9 @@
                sc->sc_defaultscreen_descr.capabilities = ri->ri_caps;
                sc->sc_defaultscreen_descr.nrows = ri->ri_rows;
                sc->sc_defaultscreen_descr.ncols = ri->ri_cols;
-               glyphcache_init(&sc->sc_gc, sc->sc_height,
+               glyphcache_init(&sc->sc_gc, sc->sc_height + 5,
                                sc->sc_width,
-                               (0x800000 / sc->sc_stride) - sc->sc_height,
+                               (0x800000 / sc->sc_stride) - sc->sc_height - 5,
                                ri->ri_font->fontwidth,
                                ri->ri_font->fontheight,
                                defattr);
@@ -946,7 +946,7 @@
        int i, x, y, wi, he, r, g, b, aval;
        int r1, g1, b1, r0, g0, b0, fgo, bgo;
        uint8_t *data8;
-       int rv;
+       int rv, cnt = 0;
 
        if (sc->sc_mode != WSDISPLAYIO_MODE_EMUL) 
                return;
@@ -1007,6 +1007,9 @@
 #define R3G3B2(r, g, b) ((r & 0xe0) | ((g >> 3) & 0x1c) | (b >> 6))
        bg8 = R3G3B2(r0, g0, b0);
        fg8 = R3G3B2(r1, g1, b1);
+
+       r128fb_wait(sc, 16);
+
        for (i = 0; i < ri->ri_fontscale; i++) {
                aval = *data8;
                if (aval == 0) {
@@ -1031,6 +1034,11 @@
                         * out 
                         */
                        latch = 0;
+                       cnt++;
+                       if (cnt > 15) {
+                               r128fb_wait(sc, 16);
+                               cnt = 0;
+                       }
                }
                data8++;
        }