pcie-iproc: broken 2nd (& 3rd?) controller support by c3245a566400 ("PCI: iproc: Request host bridge window resources")

[Bjorn Helgaas]

On Fri, Mar 10, 2017 at 05:02:48PM +0100, Rafał Miłecki wrote:
> On 03/09/2017 07:22 PM, Bjorn Helgaas wrote:
> >On Thu, Mar 09, 2017 at 08:39:07AM +0100, Rafał Miłecki wrote:
> >>On 03/08/2017 01:56 PM, Rafał Miłecki wrote:
> >>>I just tried upgrading BCM5301X from 4.4 to 4.9 and noticed I don't see card
> >>>connected to the 2nd controller.
> >>>
> >>>pcie_iproc_bcma bcma0:7: PCI host bridge to bus 0000:00
> >>>pci_bus 0000:00: root bus resource [mem 0x08000000-0x0fffffff]
> >>>pcie_iproc_bcma bcma0:7: link: UP
> >>>PCI: bus0: Fast back to back transfers disabled
> >>>pci 0000:00:00.0: bridge configuration invalid ([bus 00-00]), reconfiguring
> >>>PCI: bus1: Fast back to back transfers disabled
> >>>pci 0000:00:00.0: BAR 8: assigned [mem 0x08000000-0x080fffff]
> >>>pci 0000:01:00.0: BAR 0: assigned [mem 0x08000000-0x08007fff 64bit]
> >>>pci 0000:00:00.0: PCI bridge to [bus 01]
> >>>pci 0000:00:00.0:   bridge window [mem 0x08000000-0x080fffff]
> >>>
> >>>pcie_iproc_bcma bcma0:8: resource collision: [mem 0x40000000-0x47ffffff] conflicts with PCIe MEM space [mem 0x40000000-0x47ffffff]
> >>>pcie_iproc_bcma bcma0:8: PCIe controller setup failed
> >>>pcie_iproc_bcma: probe of bcma0:8 failed with error -16
> >>>
> >>>
> >>>This used to work with older kernels because there wasn't any collision check:
> >>>
> >>>pcie_iproc_bcma bcma0:7: PCI host bridge to bus 0000:00
> >>>pci_bus 0000:00: root bus resource [mem 0x08000000-0x0fffffff]
> >>>pcie_iproc_bcma bcma0:7: link: UP
> >>>PCI: bus0: Fast back to back transfers disabled
> >>>pci 0000:00:00.0: bridge configuration invalid ([bus 00-00]), reconfiguring
> >>>PCI: bus1: Fast back to back transfers disabled
> >>>pci 0000:00:00.0: BAR 8: assigned [mem 0x08000000-0x080fffff]
> >>>pci 0000:01:00.0: BAR 0: assigned [mem 0x08000000-0x08007fff 64bit]
> >>>pci 0000:00:00.0: PCI bridge to [bus 01]
> >>>pci 0000:00:00.0:   bridge window [mem 0x08000000-0x080fffff]
> >>>
> >>>pcie_iproc_bcma bcma0:8: PCI host bridge to bus 0001:00
> >>>pci_bus 0001:00: root bus resource [mem 0x40000000-0x47ffffff]
> >>>pcie_iproc_bcma bcma0:8: link: UP
> >>>PCI: bus0: Fast back to back transfers disabled
> >>>pci 0001:00:00.0: bridge configuration invalid ([bus 00-00]), reconfiguring
> >>>PCI: bus1: Fast back to back transfers disabled
> >>>pci 0001:00:00.0: BAR 8: assigned [mem 0x40000000-0x400fffff]
> >>>pci 0001:01:00.0: BAR 0: assigned [mem 0x40000000-0x40007fff 64bit]
> >>>pci 0001:00:00.0: PCI bridge to [bus 01]
> >>>pci 0001:00:00.0:   bridge window [mem 0x40000000-0x400fffff]
> >>>
> >>>
> >>>I guess the check is OK after all and the real problem is iproc driver assigning
> >>>the same resource.
> >>>
> >>>Broadcom team: could you take a look at this, please?
> >>
> >>I found a reason of this conflict (and probably random crashes I started
> >>seeing with 4.9). I believe we have a memory corruption.
> >
> >Yep, we're using a resource structure on the stack when we shouldn't.  Can
> >you try the patch below?
> 
> Works great! Will you push it with
> Cc: stable at vger.kernel.org # v4.8+
> please?

Thanks for testing this.  I applied the patch (with the braces fix) to
for-linus for v4.11.

> >(...)
> > 	if (ret)
> > 		dev_err(dev, "PCIe controller setup failed\n");
> >-
> >-	pci_free_resource_list(&res);
> >+		pci_free_resource_list(&resources);
> >+		return ret;
> >+	}
> 
> Works great, except it doesn't compile (braces) ;)