tridentfb: various pixclock and timing improvements
This patch fixes few issues related to timings and pixclock generation:
- disallow the pixclocks with numerator lower than
double denominator. This fixes display instability
for some modes.
- choose the pixelclock with the highest
numerator and denominator values. This improve
image quality and fixes display instability
for some modes.
- make interlaced modes work.
- set synchronization pulses polarization
correctly.
- horizontal synchronization timing are now
the same as generated by X.
Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/drivers/video/tridentfb.c b/drivers/video/tridentfb.c
index d896dee..ff82ec1 100644
--- a/drivers/video/tridentfb.c
+++ b/drivers/video/tridentfb.c
@@ -680,10 +680,12 @@
d = 20000;
for (k = 1; k >= 0; k--)
- for (m = 0; m < 32; m++)
- for (n = 0; n < 122; n++) {
+ for (m = 0; m < 32; m++) {
+ n = 2 * (m + 2) - 8;
+ for (n = (n < 0 ? 0 : n); n < 122; n++) {
fi = ((14318l * (n + 8)) / (m + 2)) >> k;
- if ((di = abs(fi - freq)) < d) {
+ di = abs(fi - freq);
+ if (di <= d) {
d = di;
best_n = n;
best_m = m;
@@ -692,6 +694,7 @@
if (fi > freq)
break;
}
+ }
if (is_oldclock(par->chip_id)) {
lo = best_n | (best_m << 7);
@@ -977,8 +980,8 @@
debug("enter\n");
hdispend = var->xres / 8 - 1;
- hsyncstart = (var->xres + var->right_margin) / 8 - 1;
- hsyncend = (var->xres + var->right_margin + var->hsync_len) / 8 - 1;
+ hsyncstart = (var->xres + var->right_margin) / 8;
+ hsyncend = (var->xres + var->right_margin + var->hsync_len) / 8;
htotal = (var->xres + var->left_margin + var->right_margin +
var->hsync_len) / 8 - 5;
hblankstart = hdispend + 1;
@@ -991,8 +994,22 @@
vblankstart = vdispend + 1;
vblankend = vtotal;
+ if (info->var.vmode & FB_VMODE_INTERLACED) {
+ vtotal /= 2;
+ vdispend /= 2;
+ vsyncstart /= 2;
+ vsyncend /= 2;
+ vblankstart /= 2;
+ vblankend /= 2;
+ }
+
crtc_unlock(par);
write3CE(par, CyberControl, 8);
+ tmp = 0xEB;
+ if (var->sync & FB_SYNC_HOR_HIGH_ACT)
+ tmp &= ~0x40;
+ if (var->sync & FB_SYNC_VERT_HIGH_ACT)
+ tmp &= ~0x80;
if (par->flatpanel && var->xres < nativex) {
/*
@@ -1000,7 +1017,7 @@
* than requested resolution decide whether
* we stretch or center
*/
- t_outb(par, 0xEB, VGA_MIS_W);
+ t_outb(par, tmp | 0xC0, VGA_MIS_W);
shadowmode_on(par);
@@ -1010,7 +1027,7 @@
screen_stretch(par);
} else {
- t_outb(par, 0x2B, VGA_MIS_W);
+ t_outb(par, tmp, VGA_MIS_W);
write3CE(par, CyberControl, 8);
}
@@ -1071,6 +1088,10 @@
tmp = (info->var.vmode & FB_VMODE_INTERLACED) ? 0x84 : 0x80;
/* enable access extended memory */
write3X4(par, CRTCModuleTest, tmp);
+ tmp = read3CE(par, MiscIntContReg) & ~0x4;
+ if (info->var.vmode & FB_VMODE_INTERLACED)
+ tmp |= 0x4;
+ write3CE(par, MiscIntContReg, tmp);
/* enable GE for text acceleration */
write3X4(par, GraphEngReg, 0x80);