Re: PROBLEM: Devices behind PCI Express-to-PCI bridge not mapped

Andreas Koch
2005-06-09T00:31:36Z

On Thu, Jun 09, 2005 at 02:36:39AM +0400, Ivan Kokshaysky wrote:
> On Wed, Jun 08, 2005 at 07:34:09PM +0200, Andreas Koch wrote:
> > However, after pci_assign_unassigned_resources() has been called, the
> > MEM and PREFETCH regions of the bridge 0000:00:1e.0 (bridge 1) _remain_
> > invalid at 0x00000000.
>
> I believe it was _IO_ and PREFETCH (unused windows of that bridge).
> Indeed, IO at 0 is fatal...

I haven't tried the patch yet, but had time to check the debug output
again. And for the bridge 0000:00:1e.0, it definitely lists all
_three_ characteristics (IO, MEM and PREFETCH) as zero. I'll let you
know how the patch turns out.

Andreas

>
> Here is additional patch which ensures unused windows of the transparent
> bridge are disabled.
>
> Ivan.
>
> --- linux/drivers/pci/setup-bus.c~ Sun Jun 5 18:37:57 2005
> +++ linux/drivers/pci/setup-bus.c Thu Jun 9 01:28:42 2005
> @@ -156,7 +156,7 @@ pci_setup_bridge(struct pci_bus *bus)
>
> /* Set up the top and bottom of the PCI I/O segment for this bus. */
> pcibios_resource_to_bus(bridge, &region, &b_res[0]);
> - if (b_res[0].flags & IORESOURCE_IO) {
> + if ((b_res[0].flags & IORESOURCE_IO) && (region.end > region.start)) {
> pci_read_config_dword(bridge, PCI_IO_BASE, &l);
> l &= 0xffff0000;
> l |= (region.start >> 8) & 0x00f0;
> @@ -182,7 +182,7 @@ pci_setup_bridge(struct pci_bus *bus)
> /* Set up the top and bottom of the PCI Memory segment
> for this bus. */
> pcibios_resource_to_bus(bridge, &region, &b_res[1]);
> - if (b_res[1].flags & IORESOURCE_MEM) {
> + if ((b_res[1].flags & IORESOURCE_MEM) && (region.end > region.start)) {
> l = (region.start >> 16) & 0xfff0;
> l |= region.end & 0xfff00000;
> DBG(KERN_INFO " MEM window: %08lx-%08lx\n",
> @@ -201,7 +201,8 @@ pci_setup_bridge(struct pci_bus *bus)
>
> /* Set up PREF base/limit. */
> pcibios_resource_to_bus(bridge, &region, &b_res[2]);
> - if (b_res[2].flags & IORESOURCE_PREFETCH) {
> + if ((b_res[2].flags & IORESOURCE_PREFETCH) &&
> + (region.end > region.start)) {
> l = (region.start >> 16) & 0xfff0;
> l |= region.end & 0xfff00000;
> DBG(KERN_INFO " PREFETCH window: %08lx-%08lx\n",

--
Prof. Dr. Andreas Koch koch@esa.informatik.tu-darmstadt.de
Technische Universitaet Darmstadt, FB20 Phone : x49-6151-16-4378
FG Embedded Systems and their Applications (ESA) FAX : x49-6151-16-5472
Hochschulstr. 10, D-64289 Darmstadt, Germany * PGP key available *