Re: regression caused by: genirq: do not leave interupts enabled on free_irq

[Thomas Gleixner <tglx@linutronix.de>]

On Fri, 11 Apr 2008, Eric W. Biederman wrote:
> On Fri, 2008-04-11 at 00:17 -0700, Yinghai Lu wrote:
> > On Fri, Apr 11, 2008 at 12:14 AM, Yinghai Lu <yhlu.kernel@gmail.com> wrote:
> > > On Fri, Apr 11, 2008 at 12:01 AM, Thomas Gleixner <tglx@linutronix.de> wrote:
> > >  > On Thu, 10 Apr 2008, Yinghai Lu wrote:
> > >  >  > last week found:
> > >  >  > after latest kernel kexec RHEL 5.1 or other stack kernel, the nvidia
> > >  >  > forcedeth doesn't work anymore.
> > >  >  >
> > >  >  > I stared at forcedeth.c two days. and revert every patches about that
> > >  >  > doesn't help.
> > >  >
> > >  >  So forcedeth does not come up again, when you kexec from linus.git
> > >  >  into an older distro kernel. Or is it the other way round ?
> > >  RHEL 5.1 kexec RHEL 5.1 : works
> > >  RHEL 5.1 kexec linus kernel: works
> > >  linus (after -rc2) kexec linus tree: works:
> > >  linus  (after -rc2) kexec RHEL 5.1 : forcedeth will not come up
> > >  linus ( before -rc2 include rc2) kexec RHEL 5.1 works
> > >
> > the forcedeth can not get IP address...
> 
> Sounds like you are not getting any interrupts when you receive a
> packet.  (i.e. The interrupt line is staying disabled).
> 
> Is MSI an option here?  I'm wondering if we disable the MSI and
> something is not enabling it.

Hmm, we disable the interrupt on free_irq(), but we reenable it in
request_irq()/setup_irq(), which is called when the forcedeth driver
initializes in the kexeced kernel. So there is some other deeper down
problem lurking.

Yinghai, can you apply that patch to RHEL 5.1 and check, what happens
if you do:

modprobe forcedeth
ifup ...
ifdown ...
rmmod forcedeth
modprobe forcedeth
ifup ...

This should result in the same problem, but probably simpler to debug.

Thanks,
	tglx