Re: [PATCH 2.6.30-rc4] r8169: avoid losing MSI interrupts

David Dillow [off-list ref] writes:

On Sat, 2009-08-22 at 05:07 -0700, Eric W. Biederman wrote:

quoted

ebiederm@xmission.com (Eric W. Biederman) writes:

quoted

David Dillow [off-list ref] writes:

quoted

Re-looking at the code, I'd guess that some IRQ status line is getting
stuck high, but I don't see why -- we should acknowledge all outstanding
interrupts each time through the loop, whether we care about them or
not.

Could reproduce a problem with the following patch applied, and send the
full dmesg, please?

Here is what I get.

r8169 screaming irq status 00000085 mask 0000ffff event 0000803f napi 0000001d

And now that the machine has come out of it, that was followed by:
Looks like the soft lockup did not manage to trigger in this case.

I need some more context, please. What is the network load through this
NIC when you have the issues? Light, heavy? Can you give me more details
about the machine? A full dmesg from boot until this happens would help
quite a bit. At a minimum it would help answer which version of the chip
we're dealing with and what the machine it is in looks like.

Can you reproduce this with pci=nomsi? I'm assuming it the chip running
in MSI mode.

Also, can you reproduce it when booting UP (or maxcpus=1)? I'm thinking
about a race between rtl8169_interrupt() and rtl8169_poll(), but it
isn't jumping out at me.

Also, I'm having connectivity troubles this weekend, so my response may
be spotty. :(

When I decode the bits in status they are TxOK, RxOK and TxDescUnavail so it looks
there is some bidirectional communication going on.

Do we really want to loop when those bits are set?

Perhaps we want to remove them from rtl_cfg_infos for the part?

Eric