Re: 2.6.20-rc7: known regressions (v2) (part 1)

[Adam Kropelin]

Eric W. Biederman wrote:
> Auke Kok <auke-jan.h.kok@xxxxxxxxx> writes:
>
> > maybe I've been unclear, but here's how e1000 detects link changes:
> >
> > 1) by checking every 2 seconds in the watchdog by reading PHY
> > registers 2) by receiving an interrupt from the NIC with the LSI bit
> > in the interrupt control register
> >
> > if the link is down to start with, the watchdog will obviously spot
> > a 'link up' change since it doesn't use any interrupts.
> >
> > The link interrupt (LSI) is a generic interrupt that comes over the
> > same vector (be it MSI or not) as RX interrupts, and in your case
> > doesn't arrive at all, which should be demonstrateable if you set
> > e.g. the watchdog interval to 30 seconds and unplug the cable - the
> > driver won't spot the link change until the watchdog fires a lot
> > later than you unplugged the cable.
> >
> > > The behavior I observe on 2.6.19 is better than 2.6.20-rc7. Link
> > > status interrupts seem to work but rx/tx does not. A few more
> > > details here:
> > <http://www.kroptech.com/~adk0212/mailimport/showmsg.php?msg_id=3339092450&db_name=linux_kernel>
>
> Can I get the corresponding lspci -xxx output.  I suspect the BIOS
> did not program the hypertransport MSI mapping capabilities correctly.
> All it has to do is set the enable but still, occasionally BIOS
> writers miss the most amazing things.

Here you go. This is from 2.6.20-rc7.

--Adam

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