Module Name: src
Committed By: bouyer
Date: Sun Apr 12 20:00:42 UTC 2015
Modified Files:
src/sys/arch/arm/omap: tifb.c
Log Message:
flushing the framebuffer from interrupt has several problems:
- As pointed out by Jared McNeill, this doesn't work for cold
or ddb. Some specific handing for these cases would be needed,
but there's no easy way to know if we're in ddb or not.
- periodic bus_dmamap_sync() of the whole framebuffer isn't cheap (about
3% CPU constant on the beaglebone back).
instead map the framebuffer BUS_DMA_PREFETCHABLE (undocumented flag, but
is MI and properly handled by arm). This allows write-combining,
which, in addition with a shadow framebuffer for rasops(9) gives
a good performance boost too (difference with the cached+sync from intr
isn't noticeable on a boot sequence).
For X11, the framebuffer was already mapped BUS_DMA_PREFETCHABLE.
A few tests shows that mapping it fully cached doesn't make a noticeable
difference either (with or without xorg's shadow framebuffer).
To generate a diff of this commit:
cvs rdiff -u -r1.4 -r1.5 src/sys/arch/arm/omap/tifb.c
Please note that diffs are not public domain; they are subject to the
copyright notices on the relevant files.
Modified files:
Index: src/sys/arch/arm/omap/tifb.c
diff -u src/sys/arch/arm/omap/tifb.c:1.4 src/sys/arch/arm/omap/tifb.c:1.5
--- src/sys/arch/arm/omap/tifb.c:1.4 Sat Apr 11 13:44:14 2015
+++ src/sys/arch/arm/omap/tifb.c Sun Apr 12 20:00:42 2015
@@ -1,4 +1,4 @@
-/* $NetBSD: tifb.c,v 1.4 2015/04/11 13:44:14 bouyer Exp $ */
+/* $NetBSD: tifb.c,v 1.5 2015/04/12 20:00:42 bouyer Exp $ */
/*
* Copyright (c) 2010 Michael Lorenz
@@ -57,7 +57,7 @@
*/
#include <sys/cdefs.h>
-__KERNEL_RCSID(0, "$NetBSD: tifb.c,v 1.4 2015/04/11 13:44:14 bouyer Exp $");
+__KERNEL_RCSID(0, "$NetBSD: tifb.c,v 1.5 2015/04/12 20:00:42 bouyer Exp $");
#include "opt_omap.h"
@@ -68,6 +68,7 @@ __KERNEL_RCSID(0, "$NetBSD: tifb.c,v 1.4
#include <sys/malloc.h>
#include <sys/lwp.h>
#include <sys/kauth.h>
+#include <sys/kmem.h>
#include <uvm/uvm_extern.h>
@@ -155,6 +156,7 @@ struct tifb_softc {
int sc_stride;
int sc_locked;
void *sc_fbaddr, *sc_vramaddr;
+ void *sc_shadowfb;
bus_addr_t sc_fbhwaddr;
uint16_t *sc_palette;
@@ -395,6 +397,12 @@ tifb_attach(device_t parent, device_t se
sc->sc_vramsize = sc->sc_palettesize +
sc->sc_stride * sc->sc_panel->panel_height;
+ sc->sc_shadowfb = kmem_alloc(sc->sc_vramsize - sc->sc_palettesize,
+ KM_NOSLEEP);
+ if (sc->sc_shadowfb == NULL) {
+ aprint_error_dev(sc->sc_dev,
+ "warning: failed to allocate shadow framebuffer\n");
+ }
if (bus_dmamem_alloc(sc->sc_dmat, sc->sc_vramsize, 0, 0,
sc->sc_dmamem, 1, &segs, BUS_DMA_NOWAIT) != 0) {
aprint_error_dev(sc->sc_dev,
@@ -403,7 +411,7 @@ tifb_attach(device_t parent, device_t se
}
if (bus_dmamem_map(sc->sc_dmat, sc->sc_dmamem, 1, sc->sc_vramsize,
- &sc->sc_vramaddr, BUS_DMA_NOWAIT) != 0) {
+ &sc->sc_vramaddr, BUS_DMA_NOWAIT | BUS_DMA_PREFETCHABLE) != 0) {
aprint_error_dev(sc->sc_dev, "failed to map video RAM\n");
return;
}
@@ -543,7 +551,7 @@ tifb_attach(device_t parent, device_t se
timing0, timing1, timing2);
/* DMA settings */
- reg = LCDDMA_CTRL_FB0_FB1;
+ reg = 0;
/* Find power of 2 for current burst size */
switch (sc->sc_panel->dma_burst_sz) {
case 1:
@@ -597,9 +605,7 @@ tifb_attach(device_t parent, device_t se
TIFB_WRITE(sc, LCD_CLKC_RESET, 0);
aprint_debug_dev(self, ": LCD_CLKC_ENABLE 0x%x\n", TIFB_READ(sc, LCD_CLKC_ENABLE));
- reg = IRQ_EOF1 | IRQ_EOF0 | IRQ_FUF | IRQ_PL |
- IRQ_ACB | IRQ_SYNC_LOST | IRQ_RASTER_DONE |
- IRQ_FRAME_DONE;
+ reg = IRQ_FUF | IRQ_PL | IRQ_ACB | IRQ_SYNC_LOST;
TIFB_WRITE(sc, LCD_IRQENABLE_SET, reg);
reg = TIFB_READ(sc, LCD_RASTER_CTRL);
@@ -653,6 +659,8 @@ tifb_attach(device_t parent, device_t se
config_found(sc->sc_dev, &aa, wsemuldisplaydevprint);
}
+uint32_t tifb_intr_unh = 0;
+
static int
tifb_intr(void *v)
{
@@ -686,12 +694,6 @@ tifb_intr(void *v)
return 0;
}
- if (reg & (IRQ_FRAME_DONE|IRQ_EOF0|IRQ_EOF1)) {
- /* flush the write-back cache */
- bus_dmamap_sync(sc->sc_dmat, sc->sc_dmamap,
- 0, sc->sc_vramsize, BUS_DMASYNC_PREWRITE);
- }
-
if (reg & IRQ_FRAME_DONE) {
ev_frame_done.ev_count ++;
reg &= ~IRQ_FRAME_DONE;
@@ -724,8 +726,10 @@ tifb_intr(void *v)
/* TODO: Handle ACB */
reg =~ IRQ_ACB;
}
- if (reg)
+ if (reg) {
ev_others.ev_count ++;
+ tifb_intr_unh = reg;
+ }
return 0;
}
@@ -850,8 +854,14 @@ tifb_init_screen(void *cookie, struct vc
ri->ri_height = sc->sc_panel->panel_height;
ri->ri_stride = sc->sc_stride;
ri->ri_flg = RI_CENTER | RI_FULLCLEAR;
-
- ri->ri_bits = (char *)sc->sc_fbaddr;
+
+ if (sc->sc_shadowfb != NULL) {
+ ri->ri_bits = (char *)sc->sc_shadowfb;
+ ri->ri_hwbits = (char *)sc->sc_fbaddr;
+ } else {
+ ri->ri_bits = (char *)sc->sc_fbaddr;
+ ri->ri_hwbits = NULL;
+ }
if (existing) {
ri->ri_flg |= RI_CLEAR;
