Re: skge error; hangs w/ hardware memory hole

On Mon, 3 Jul 2006 22:52:38 +0200
Martin Michlmayr [off-list ref] wrote:

We received the following bug report at http://bugs.debian.org/341801

| I have a Asus A8V with 4GB of RAM. When I turn on the hardware memory
| hole in the BIOS, the skge driver prints out this message:
|       skge hardware error detected (status 0xc00)
| and then does not work. Setting debug=16 doesn't really show anything.

Another users confirms this bug, saying:

| I'm running kernel 2.6.15-1-amd64-generic version 2.6.15-6, and see
| the very same thing.
| So I have to turn off the memory remapping feature that allows the
| system to see all 4 gig of memory, and thus lose the use of about 200
| megabytes of memory.
| Hardware: ASUS A8V Deluxe, 4G RAM, Athlon 64 3200+ CPU.

This problem has probably been there forever and also happens with the
sk98lin driver:

| With sk98lin under both 2.6.12 and 2.6.17 I get the following message,
| repeated countless times, and finally a hang: [this is copied from
| screen on to a sheet a paper and re-typed, beware typos]:

| eth0: Adapter failed
| eth0: -- ERROR --
| class: Hardware failure
| Nr: 0x264
| Msg: unexpected IRQ Status error

The bug is still present in 2.6.17 -mm6:

| -mm6 does not work with skge and the hardware memory hole. It gave
| these messages:

| skge eth0: enabling interface
| skge 0000:00:0a.0: PCI error cmd=0x117 status=0x22b0
| skge unable to clear error (so ignoring them)
| skge eth0: Link is up at 1000 Mbps, full duplex, flow control tx and rx

| DHCP never managed to get an IP address.

Any idea what to do about this?

I don't really have access to the hardware, or know the x86-64 details perhaps Andi Kleen 
would be of more help. But my suspicion is that the remapping doesn't work for i/o devices
because of hardware or BIOS.  One simple workaround is to force use of the I/O mmu on
the amd64 processor. This has a small performance impact (requires more setup).

See Documentation/x86_64/boot-options.txt iommu=force

-- 
Stephen Hemminger [off-list ref]
Quis custodiet ipsos custodes?