Re: [Bug] pci allocation resources problems on x86_64

From: Jesse Barnes
Date: Fri Oct 24 2008 - 14:32:11 EST


On Friday, October 24, 2008 3:34 am Mathieu Taillefumier wrote:
> Hi
>
> Sorry, the first files iomem and ioports are not the right one (I used
> the mem option to check if it has any effects). Please find the right
> one in attachments. Sorry again for this mistake.
>
> regards
>
> Mathieu
>
> > Hi,
> >
> > The kernel does not seems to allocate the pci resources correctly on
> > sony laptop (VGN-SZ71 series) when pcmcia slot is used.
> >
> > I track down this bug for long now and I was able to identify where it
> > is probably coming from. The laptop I am using possess a pcmcia card
> > slot that I am using for a tvcard. The kernel is a x86_64 bits kernel
> > (2.6.27.2) and the laptop has 4G of memory. In this case the
> > initialization of the tv-card is pure garbage and the kernel oops
> > after that. Now if I start the laptop with 2G and the same kernel then
> > everything works fine. From that I can assume that the problem does
> > not come from the tvcard driver and maybe not from the pcmcia driver
> > (although I am not completely sure). After discussing on the dvb
> > mailling list we arrive to the conclusion that the problem is probably
> > coming from pci allocation ressources.
> >
> > additional informations :
> >
> > Configurations that work
> >
> > - x86_64 kernels with 2G of memory
> > - x86 kernels with 4G of memory without PAE activated nor 64 bits
> > resources allocations option activated.
> >
> > Config that do not work
> >
> > - x86_64 kernels with 4G of memory
> > - x86 kernels with 4G of memory with 64bits resources allocation
> > activated (without PAE).
> >
> > The problem can be reproduced with kernel-next and the kernel-git so
> > far and probably with earlier kernels although I have try this
> >
> > cat /proc/version
> > Linux version 2.6.27.2-intel-nogem (root@coesite) (gcc version 4.3.1
> > (GCC) ) #4 SMP Wed Oct 22 12:05:55 CEST 2008
> > the lspci output are in one of the files and different dmesg are
> > included. the dmesg-diff give the differences between the working one
> > and the buggy one.
> >
> > I would like to help debugging this

Ultimately we need to do better at grabbing space for PCI allocations on x86.
I was hoping we'd have some patches in 2.6.28 that would help here, but they
weren't ready in time. Can you file a kernel.org bug for this problem with
the files attached? I'll try to find time to put together some
improvements...

--
Jesse Barnes, Intel Open Source Technology Center

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