tridentfb: improved register values on TGUI 9680

Improved values for some registers after Xorg Trident driver.  The main
problem was that values set by BIOS have been ignored.

This patch completely remove random pixels ("snow") on the TGUI 9680 and
9440 (not supported yet by the driver).  It does not help with the "snow"
on 3DImage and Blade3D cards.

There is also small improvement in timing calculations (hblank start and
vblank start)

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>

drivers/video/tridentfb.c

@@ -87,7 +87,17 @@ MODULE_PARM_DESC(crt, "Define if CRT is connected");
 
 static int is_oldclock(int id)
 {
-	return (id == TGUI9660);
+	return	(id == TGUI9660) ||
+		(id == CYBER9320);
+}
+
+static int is_oldprotect(int id)
+{
+	return	(id == TGUI9660) ||
+		(id == PROVIDIA9685) ||
+		(id == CYBER9320) ||
+		(id == CYBER9382) ||
+		(id == CYBER9385);
 }
 
 static int is_blade(int id)
@@ -143,6 +153,7 @@ static int iscyber(int id)
 
 	case CYBER9320:
 	case TGUI9660:
+	case PROVIDIA9685:
 	case IMAGE975:
 	case IMAGE985:
 	case BLADE3D:
@@ -905,14 +916,14 @@ static int tridentfb_set_par(struct fb_info *info)
 	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;
+	hblankstart = hdispend + 1;
 	hblankend = htotal + 3;
 
 	vdispend = var->yres - 1;
 	vsyncstart = var->yres + var->lower_margin;
 	vsyncend = vsyncstart + var->vsync_len;
 	vtotal = var->upper_margin + vsyncend - 2;
-	vblankstart = vdispend + 2;
+	vblankstart = vdispend + 1;
 	vblankend = vtotal;
 
 	crtc_unlock(par);
@@ -1020,15 +1031,18 @@ static int tridentfb_set_par(struct fb_info *info)
 
 	write3X4(par, PixelBusReg, tmp);
 
-	tmp = 0x10;
+	tmp = read3X4(par, DRAMControl);
+	if (!is_oldprotect(par->chip_id))
+		tmp |= 0x10;
 	if (iscyber(par->chip_id))
 		tmp |= 0x20;
 	write3X4(par, DRAMControl, tmp);	/* both IO, linear enable */
 
 	write3X4(par, InterfaceSel, read3X4(par, InterfaceSel) | 0x40);
-	write3X4(par, Performance, 0x92);
+	if (!is_xp(par->chip_id))
+		write3X4(par, Performance, read3X4(par, Performance) | 0x10);
 	/* MMIO & PCI read and write burst enable */
-	write3X4(par, PCIReg, 0x07);
+	write3X4(par, PCIReg, read3X4(par, PCIReg) | 0x06);
 
 	/* convert from picoseconds to kHz */
 	vclk = PICOS2KHZ(info->var.pixclock);
@@ -1230,6 +1244,9 @@ static int __devinit trident_pci_probe(struct pci_dev *dev,
 		revision = vga_io_rseq(RevisionID);
 
 		switch (revision) {
+		case 0x21:
+			chip_id = PROVIDIA9685;
+			break;
 		case 0x22:
 		case 0x23:
 			chip_id = CYBER9397;

include/video/trident.h

@@ -25,6 +25,7 @@
 #define CYBER9520	0x9520
 #define CYBER9525DVD	0x9525
 #define TGUI9660	0x9660
+#define PROVIDIA9685	0x9685
 #define IMAGE975	0x9750
 #define IMAGE985	0x9850
 #define BLADE3D		0x9880