PATCH 2.5.x disable BAR when sizing

[grundler@cup.hp.com (Grant Grundler)]

Martin,
In April 2002, turukawa@icc.melco.co.jp sent a 2.4.x patch to disable
BARs while the BARs were being sized.  I've "forward ported" this patch
to 2.5.x (appended).  turukawa's excellent problem description and
original posting are here:
	https://lists.linuxia64.org/archives//linux-ia64/2002-April/003302.html

David Mosberger agrees this is an "obvious fix".
We've been using this in the ia64 2.4 code stream since about August.

thanks,
grant


Index: drivers/pci/probe.c
===================================================================
RCS file: /var/cvs/linux-2.5/drivers/pci/probe.c,v
retrieving revision 1.2
diff -u -p -r1.2 probe.c
--- drivers/pci/probe.c	9 Oct 2002 20:42:57 -0000	1.2
+++ drivers/pci/probe.c	17 Dec 2002 21:53:14 -0000
@@ -48,6 +48,12 @@ static void pci_read_bases(struct pci_de
 	unsigned int pos, reg, next;
 	u32 l, sz;
 	struct resource *res;
+	u16 cmd;
+
+	/* Disable I/O & memory decoding while we size the BARs. */
+	pci_read_config_word(dev, PCI_COMMAND, &cmd);
+	pci_write_config_word(dev, PCI_COMMAND,
+		cmd & ~(PCI_COMMAND_IO | PCI_COMMAND_MEMORY));
 
 	for(pos=0; pos<howmany; pos = next) {
 		next = pos+1;
@@ -114,6 +120,8 @@ static void pci_read_bases(struct pci_de
 		}
 		res->name = dev->name;
 	}
+
+	pci_write_config_word(dev, PCI_COMMAND, cmd);
 }
 
 void __devinit pci_read_bridge_bases(struct pci_bus *child)