Re: PCI BAR1 Unassigned

[Jan Zwiegers <jan@radicalsystems.co.za>]

On 2011-05-19 08:50 PM, Bjorn Helgaas wrote:
> On Thu, May 19, 2011 at 10:28 AM, Jan Zwiegers<jan@radicalsystems.co.za>  wrote:
>> I have the problem below where my PCI card's second BAR does not get
>> assigned.
>> What can be the cause of this problem?
>> The last kernel I tested on which worked OK was 2.6.27.
>> My current problematic kernel 2.6.35.
>>
>> 05:01.0 Unassigned class [ff00]: Eagle Technology PCI-703 Analog I/O Card
>> (rev 5c)
>>     Flags: bus master, slow devsel, latency 32, IRQ 22
>>     Memory at 93b00000 (type 3, prefetchable) [size=2K]
>>     Memory at<unassigned>  (type 3, prefetchable)
>>     Capabilities: [80] #00 [0600]
>>     Kernel modules: pci703drv
>
> Could be resource exhaustion or, more likely, we ran out because we
> now assign resource to things that don't need them, leaving none for
> things that *do* need them.  This sounds like a regression, so we
> should open a bugzilla for it and attach dmesg logs from 2.6.27 and
> 2.6.35.
>
> Does this problem keep the driver from working?  (Sometimes drivers
> don't actually use all the BARs a device supports.)
>
> Bjorn
>

I'm the maintainer of the driver and was involved in the development of 
the board as well in 2003. The board uses two BARS and the second BAR is 
the most important. The board worked fine since the 2.4 days and only 
recently became problematic. I suspect it works on even later kernels 
than 27, maybe 2.6.32.

My knowledge is too little to actually determine if the problem is 
because the FPGA based PCI interface is not within spec or something 
that changed in the kernel, because of the post .30 releases becoming 
more strict to PCI specification, i.e. BIOS / Kernel interaction.

Jan