Re: [Bug #12337] ~100 extra wakeups reported by powertop

Alberto Gonzalez
2009-02-24T17:05:07Z

--- On Tue, 2/24/09, Jesse Barnes <jbarnes@virtuousgeek.org> wrote:

> > Steps:
> > - Boot into Fedora 10 Live CD (obviously, into the
> default graphical mode)
> > - Install Powertop (yum install powertop) and run it
> > - I get about 60 wakeups per second from i915@pci....
> leaving the system
> > idle - Switch to console and back to X. The wakeups
> are gone.
>
> Ah ok, it sounds like you're getting vblank interrupts
> at startup time, but
> once you VT switch the kernel figures out that you
> don't need them, so it
> disables them. I think this is a bug in the 2D driver; it
> has an ioctl it
> uses when doing modesetting which doubles as a
> "disabling the irq is ok"
> signal, but we call it at a time when the corresponding
> pipe is off, so the
> kernel ignores the call.

Yes, that's what E. Anholt supposed too.

>
> Can you file a bug for this at bugs.freedesktop.org? Is it
> easy for you to
> rebuild & test xf86-video-intel driver patches?

I filed the report:
http://bugs.freedesktop.org/show_bug.cgi?id=20296

Sure, I guess I can manage to patch the Intel driver and test it. I'm using 2.4.3 now, so maybe one thing I could do first is to try 2.5.x.
>
> Thanks,
> --
> Jesse Barnes, Intel Open Source Technology Center

Thanks,
Alberto.