Problem with P2P PCI bridge in pSeries 630

[linas at austin.ibm.com]

On Fri, Sep 26, 2003 at 08:22:48PM -0700, Roland Dreier wrote:
> I have an IBM pSeries 630 server, and I am attempting to port a driver
> for an InfiniBand HCA to ppc64 Linux.  (I already have the driver
> working on i386, x86_64, ia64 and ppc32) However, I'm having a problem

[ ...]

> be able to cope with the PCI bridge.  The first problem appears around
> when the kernel tries to start the framebuffer (right around when it
> prints its message about leaving prom_init).  Usually it displays four

[...]

> EEH: PCI Enhanced I/O Error Handling Enabled
> PCI: 0062:00.0 pci15b3,5a44 (<unknown type>) has bad status from firmware! (fail-perm)<4>write_OF_bars 0062:00.0 pci15b3,5a44 (<unknown type>): read BAR0 failed
> write_OF_bars 0062:00.0 pci15b3,5a44 (<unknown type>): read BAR1 failed

Before you bang your head too much on the PCI code, please make sure
that you have the latest firmware installed (and install it if you don't).

The OF firmware is involved in the PCI setup, and there have been some
bugs fixed having to do with PCI bridges.  These are 'recent' bugs,
fixed about 6 months ago.

FYI EEH is a mechanism that takes a PCI slot off-line if a PCI
parity error, data or address error etc. are detected.  Once the
slot is taken offline, reads from that slot will return 0xff and
writes will never make it to the device.  Currently the kernel will
be forced to panic if an EEH error is detected, but I guess in the
future the device will be hotplug-removed.

There were some bugs when the EEH code walked bridges.  A firmware upgrade
should fix it; if not then you've got a real problem.

--linas


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