tridentfb: fix timing calculations
Fix broken timings calculations. This patch helps with following
problems:
- no left part of screen visible (up to half of the screen)
- monitor's frequencies are not the ones intended for selected modes
- if mode with resoultion y > 1024 is selected at least once then
all modes with y < 1024 are "out of sync" (no display)
Signed-off-by: Krzysztof Helt <krzysztof.h1@wp.pl>
Cc: "Antonino A. Daplas" <adaplas@pol.net>
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 381e585..af02af1 100644
--- a/drivers/video/tridentfb.c
+++ b/drivers/video/tridentfb.c
@@ -886,20 +886,19 @@
debug("enter\n");
hdispend = var->xres / 8 - 1;
- hsyncstart = (var->xres + var->right_margin) / 8;
- hsyncend = var->hsync_len / 8;
- htotal =
- (var->xres + var->left_margin + var->right_margin +
- var->hsync_len) / 8 - 10;
- hblankstart = hdispend + 1;
- hblankend = htotal + 5;
+ hsyncstart = (var->xres + var->right_margin) / 8 - 1;
+ hsyncend = (var->xres + var->right_margin + var->hsync_len) / 8 - 1;
+ htotal = (var->xres + var->left_margin + var->right_margin +
+ var->hsync_len) / 8 - 5;
+ hblankstart = hdispend + 2;
+ hblankend = htotal + 3;
vdispend = var->yres - 1;
vsyncstart = var->yres + var->lower_margin;
- vsyncend = var->vsync_len;
- vtotal = var->upper_margin + vsyncstart + vsyncend - 2;
- vblankstart = var->yres;
- vblankend = vtotal + 2;
+ vsyncend = vsyncstart + var->vsync_len;
+ vtotal = var->upper_margin + vsyncend - 2;
+ vblankstart = vdispend + 2;
+ vblankend = vtotal;
crtc_unlock(par);
write3CE(par, CyberControl, 8);
@@ -930,7 +929,7 @@
write3X4(par, VGA_CRTC_V_SYNC_START, vsyncstart & 0xFF);
write3X4(par, VGA_CRTC_V_SYNC_END, (vsyncend & 0x0F));
write3X4(par, VGA_CRTC_V_BLANK_START, vblankstart & 0xFF);
- write3X4(par, VGA_CRTC_V_BLANK_END, 0 /* p->vblankend & 0xFF */);
+ write3X4(par, VGA_CRTC_V_BLANK_END, vblankend & 0xFF);
/* horizontal timing values */
write3X4(par, VGA_CRTC_H_TOTAL, htotal & 0xFF);
@@ -939,7 +938,7 @@
write3X4(par, VGA_CRTC_H_SYNC_END,
(hsyncend & 0x1F) | ((hblankend & 0x20) << 2));
write3X4(par, VGA_CRTC_H_BLANK_START, hblankstart & 0xFF);
- write3X4(par, VGA_CRTC_H_BLANK_END, 0 /* (p->hblankend & 0x1F) */);
+ write3X4(par, VGA_CRTC_H_BLANK_END, hblankend & 0x1F);
/* higher bits of vertical timing values */
tmp = 0x10;
@@ -953,16 +952,18 @@
if (vsyncstart & 0x200) tmp |= 0x80;
write3X4(par, VGA_CRTC_OVERFLOW, tmp);
- tmp = read3X4(par, CRTHiOrd) | 0x08; /* line compare bit 10 */
+ tmp = read3X4(par, CRTHiOrd) & 0x07;
+ tmp |= 0x08; /* line compare bit 10 */
if (vtotal & 0x400) tmp |= 0x80;
if (vblankstart & 0x400) tmp |= 0x40;
if (vsyncstart & 0x400) tmp |= 0x20;
if (vdispend & 0x400) tmp |= 0x10;
write3X4(par, CRTHiOrd, tmp);
- tmp = 0;
- if (htotal & 0x800) tmp |= 0x800 >> 11;
- if (hblankstart & 0x800) tmp |= 0x800 >> 7;
+ tmp = (htotal >> 8) & 0x01;
+ tmp |= (hdispend >> 7) & 0x02;
+ tmp |= (hsyncstart >> 5) & 0x08;
+ tmp |= (hblankstart >> 4) & 0x10;
write3X4(par, HorizOverflow, tmp);
tmp = 0x40;