Re: small PCI probe patch for odd 64 bit BARs

[Tim Hockin <thockin@google.com>]

On Thu, Nov 11, 2004 at 09:22:21AM -0800, Greg KH wrote:
> On Wed, Nov 10, 2004 at 08:48:09PM -0800, Tim Hockin wrote:
> > The current PCI probe code breaks for 64 bit BARs that do not decode a
> > full 64 bits.  Example:
> > 
> > We have a device that uses a 64 bit BAR.  When you write all Fs to the
> > BARs, you get:
> > 
> > 	000000ff ffff0000
> > 
> > It wants 64k, in the first TB of RAM.  The current code totally borks on
> > this.
> > 
> > Simple patch against 2.6.9:
> 
> As Andrew pointed out, you didn't even compile test this patch, not nice.

Yeah, I sent the 2.4 patch and called it 2.6, bny mistake.  The one that
actually came out of the 2.6.9 tree here was sent a few minutes ago, and
here again.

I was in a rush, I screwed up.  This version has been compile tested,
and run tested under 2.4.

Sorry, again.



--- linux-2.6.9/drivers/pci/probe.c.orig	2004-11-10 20:42:03.000000000 -0800
+++ linux-2.6.9/drivers/pci/probe.c	2004-11-11 09:30:07.000000000 -0800
@@ -144,9 +144,11 @@
 			pci_write_config_dword(dev, reg+4, ~0);
 			pci_read_config_dword(dev, reg+4, &sz);
 			pci_write_config_dword(dev, reg+4, l);
-			if (~sz)
-				res->end = res->start + 0xffffffff +
-						(((unsigned long) ~sz) << 32);
+			sz = pci_size(l, sz, 0xffffffff);
+			if (sz) {
+				/* This BAR needs > 4GB?  Wow. */
+				res->end |= (unsigned long)sz<<32;
+			}
 #else
 			if (l) {
 				printk(KERN_ERR "PCI: Unable to handle 64-bit address for device %s\n", pci_name(dev));