Re: Regression: 2.6.34 boot fails on E5405 system, bisected: de08e2c26

[Robert Hancock <hancockrwd@gmail.com>]

On 07/13/2010 07:17 PM, Ben Greear wrote:
> On 07/13/2010 05:36 PM, Ben Greear wrote:
>> We're seeing boot failures on multiple machines, running FC8 and
>> F11. I bisected on an FC8 32-bit system. Newer hardware works,
>> but these older ones do not.
>>
>> A console log of the hang is found later in this email.
>>
>> Please let me know if you would like any additional information,
>> and I will be happy to test patches.
>>
>> The same failure happens in 2.6.34.1, so the fix does not appear to
>> be in the stable tree yet.
>
>
> I added some printks to the offending code. It seems the problem
> is that the fixed_bar_cap method in arch/x86/pci/mrst.c loops forever:
>
> # Endless loop of this spewing to console...
>
> pcie_cap: 268435456Checking vendor..
> pos after shift: 256
> Before read..

Can you print out bus->number and devfn and look that up in lspci to 
find out which device it's hitting? It looks like there's a device with 
a PCI Express extended capability header that has a extended capability 
ID of 0000h and a next capability offset of 100h, which points to 
itself, causing the infinite loop. I'm guessing that if pcie_cap >> 20 
<= pos then it should give up and break out of the loop, since it means 
that the next capability pointer is invalidly pointing to the same or a 
previous entry..