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

[Ray Jui]

Hi Bjorn,

Thanks for helping take care of this.

Ray

On 3/10/2017 8:02 AM, 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 looking at this!
> 
> Also see below...
> 
> 
>> (...)
>>      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) ;)