[Openchrome-users] K8M890 and 3D

[icarus]

Re: K8M890 and 3D
I have similar problems with a Asus K8V-VM motherboard with a 64bit Athlon. 

I am running 2.6.20-gentoo-r7Y with xorg-server 1.3.0 ebuild for x86_64. See attached Xorg.log for details of loaded modules.

I have built the kernel modules and unichrome drivers from the experimental branch as per this article: 

[http://wiki.openchrome.org/tikiwiki/tiki-view_forum_thread.php?forumId=1&comments_parentId=3330]

All works fine apart from 3D and OpenGL just locks the screen when I run glxgears or glxinfo. With DRI enabled and loaded but Option "EnableAGPDMA"	"On" I get tight loops preventing even XDM loading. I get a black screen and cannot switch to any vt's. 

The problem appears to be in this code. From the log with this debugging enabled I get over 1.5 million lines written to Xorg.0.log of "doing MarkerReadStuff" inside the while loop. Indicating that whatever check < (1 < < 24) is doing is not getting anything from the buffer that forms a positive check;

void
viaAccelWaitMarker(ScreenPtr pScreen, int marker)
{
    ScrnInfoPtr pScrn = xf86Screens[pScreen->myNum];
    VIAPtr pVia = VIAPTR(pScrn);
    CARD32 uMarker = marker;
    DEBUG(xf86DrvMsg(pScrn->scrnIndex, X_INFO, "- Inside viaAccelWaitMarker (marker = %d)\n", marker));
    DEBUG(xf86DrvMsg(pScrn->scrnIndex, X_INFO, "- Inside viaAccelWaitMarker (pVia->agpDMA = %d)\n", pVia->agpDMA));
    
    if (pVia->agpDMA) {
	while ((pVia->lastMarkerRead - uMarker) > (1 < < 24)) {
            lastMarkerRead = *pVia->markerBuf;
	    DEBUG(xf86DrvMsg(pScrn->scrnIndex, X_INFO, "- Doing MarkerRead stuff\n"));
	}
    } else {
	DEBUG(xf86DrvMsg(pScrn->scrnIndex, X_INFO, "- Calling viaAccelSyn\n"));
	viaAccelSync(pScrn);
	DEBUG(xf86DrvMsg(pScrn->scrnIndex, X_INFO, "- Called viaAccelSync\n"));
    }
}

The lockup is due to an infinite, tight loop in this code.

Hope this helps and happy to debug further if needed.

Mike


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