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vgavesa: some nvidia cards start the framebuffer in the middle of a pci membar

--- a/sys/src/9/pc/vgavesa.c

+++ b/sys/src/9/pc/vgavesa.c

@@ -130,7 +130,6 @@

 	paddr = LONG(p+40);

 	size = WORD(p+20)*WORD(p+16);

-	size = PGROUND(size);

 	/*

 	 * figure out max size of memory so that we have

@@ -141,23 +140,25 @@

 	while(!havesize && (pci = pcimatch(pci, 0, 0)) != nil){

 		if(pci->ccrb != Pcibcdisp)

 			continue;

-		for(i=0; i<nelem(pci->mem); i++)

-			if(paddr == (pci->mem[i].bar&~0x0F)){

-				if(pci->mem[i].size > size)

-					size = pci->mem[i].size;

+		for(i=0; i<nelem(pci->mem); i++){

+			ulong a, e;

+

+			a = pci->mem[i].bar & ~0xF;

+			e = a + pci->mem[i].size;

+			if(paddr >= a && (paddr+size) <= e){

+				size = e - paddr;

 				havesize = 1;

 				break;

 			}

+		}

 	}

 	/* no pci - heuristic guess */

-	if (!havesize)

+	if(!havesize)

 		if(size < 4*1024*1024)

 			size = 4*1024*1024;

 		else

 			size = ROUND(size, 1024*1024);

-	if(size > 16*1024*1024)		/* arbitrary */

-		size = 16*1024*1024;

 	vgalinearaddr(scr, paddr, size);

 	if(scr->apsize)

-- 

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