tridentfb: Fix scrolling artifacts during disk IO

Reported by: Jochen Hein (Bugzilla Bug 4312)

When there is disk I/O happening, the framebuffer has a little snow on the screen. Once I/O has finished, no garbage remains on screen.

This bug was explained by: Knut Petersen

Most important is CRTC register 2f, signal quality is also improved for higher vclk values by changing set_vclk() according to the X drivers and cyblafb.c

Fix is to set the performance register (0x2f) with a more stable value.

From: Antonino Daplas <[email protected]>

---

tridentfb.c | 2 +-

1 files changed, 1 insertion(+), 1 deletion(-)

@@ -904,7 +904,7 @@ static int tridentfb_set_par(struct fb_i

	write3X4(DRAMControl, tmp);	//both IO,linear enable

	write3X4(InterfaceSel, read3X4(InterfaceSel) | 0x40);
-	write3X4(Performance,0x20);
+	write3X4(Performance,0x92);
	write3X4(PCIReg,0x07);		//MMIO & PCI read and write burst enable

	/* convert from picoseconds to MHz */

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Applied. However, the patch was whitespace-damaged, please don't do that. I fixed it up by hand this time.

Linus

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