Re: e100 PCI bridge problem

[William Montgomery <william@opinicus.com>]

Thanks for responding.  I am very interested to find the source of this 
problem.

Kok, Auke wrote:

> William Montgomery wrote:
>
>> In an earlier post to the list I described a hard lockup condition
>> that occurs on linux kernels 2.4.22, 2.6.13, and 2.6.17 when using
>> a 4 port 10/100 fast ethernet card.  The lockup is easily repeatable
>> and occurs on 2 out of 3 computers.
>>
>> Further testing has revealed that the lockup can be prevented on all
>> computers by making sure the card is installed on the primary PCI bus.
>> If the card is installed in a slot on the secondary PCI bus (behind a
>> PCI to PCI bridge) the lockup occurs.
>
>
> sounds like int-A/B/C/D routing issues

The strange thing is that all the ports on the card work fine for a few 
minutes, then when some condition (as yet unknown) occurs the system 
locks up hard.  I am currently using a PCI bus analyzer to capture bus 
activity just prior to the lockup to try and find out what leads up to 
this condition.

>
>> Are there any PCI tuning registers that I can tweak to get around
>> this problem?  Any changes I could make to the e100 driver to fix this?
>
>
> this issue might be resolvable by quirking the bridgee chips and 
> adjusting any APIC where needed. Unfortunately I don't know much about 
> this but it's physically not possible from the e100 driver. The 
> special (non-intel) card that has these 4 ports onboard contains a 
> bridge chip itself which explains the issues. Even a BIOS issue could 
> be the cause here.

I am aware of the bridge chip on the card but not sure what you mean 
when you say this explains the issues?  I sure would like to figure out 
a way around this.

The PCI info follows:
  00:00.0 Host bridge: Intel Corp. 82845G/GL[Brookdale-G]/GE/PE DRAM 
Controller/Host-Hub Interface (rev 03)
  00:02.0 VGA compatible controller: Intel Corp. 
82845G/GL[Brookdale-G]/GE Chipset Integrated Graphics Device (rev 03)
  00:1d.0 USB Controller: Intel Corp. 82801DB (ICH4) USB UHCI #1 (rev 02)
  00:1d.1 USB Controller: Intel Corp. 82801DB (ICH4) USB UHCI #2 (rev 02)
  00:1d.2 USB Controller: Intel Corp. 82801DB (ICH4) USB UHCI #3 (rev 02)
  00:1d.7 USB Controller: Intel Corp. 82801DB (ICH4) USB2 EHCI 
Controller (rev 02)
  00:1e.0 PCI bridge: Intel Corp. 82801BA/CA/DB/EB/ER Hub interface to 
PCI Bridge (rev 82)
  00:1f.0 ISA bridge: Intel Corp. 82801DB (ICH4) LPC Bridge (rev 02)
  00:1f.1 IDE interface: Intel Corp. 82801DB (ICH4) Ultra ATA 100 
Storage Controller (rev 02)
  00:1f.3 SMBus: Intel Corp. 82801DB/DBM (ICH4) SMBus Controller (rev 02)
  01:08.0 Ethernet controller: Intel Corp. 82801BD PRO/100 VE (CNR) 
Ethernet Controller (rev 82)
  01:0c.0 PCI bridge: Pericom Semiconductor: Unknown device 8150 (rev 02)
  02:06.0 PCI bridge: Hint Corp HB6 Universal PCI-PCI bridge 
(non-transparent mode) (rev 15)
  03:04.0 Ethernet controller: Intel Corp. 82557/8/9 [Ethernet Pro 100] 
(rev 08)
  03:05.0 Ethernet controller: Intel Corp. 82557/8/9 [Ethernet Pro 100] 
(rev 08)
  03:06.0 Ethernet controller: Intel Corp. 82557/8/9 [Ethernet Pro 100] 
(rev 08)
  03:07.0 Ethernet controller: Intel Corp. 82557/8/9 [Ethernet Pro 100] 
(rev 08)

>
> Perhaps the linuxfirmwarekit will reveal more information. In any 
> case, fixing this in software would be a gigantic effort.
>
I will look into that on Monday and report what I find.  It seems like 
it is premature to say how much effort the fix will take since the 
problem is not yet known?  At least not known to me yet.  I would just 
like to find out what parameters on the bridge/bridges might affect this 
problem and how to modify them.

> Auke
>