[Intel-gfx] i915 irq storm mitigation in 3.10

[Daniel Vetter]

On Mon, Jul 22, 2013 at 10:36 PM, Egbert Eich <eich at suse.com> wrote:
> Jan Niggemann writes:
>  > Egbert, Daniel, others,
>  > It's a Lenovo ThinkPad T400, the model is 7434-AG2.
>  > root at muretop:~# lspci -n
>  > 00:00.0 0600: 8086:2a40 (rev 07)
>  > 00:02.0 0300: 8086:2a42 (rev 07)
>
> Ok, this is a gm45.
>
>  >
>  > As to the log: I messed up the kernel parameters this morning... was
>  > out of coffee this morning and my 1,5y daughter played around me :-)
>  >
>  > Here's my kernel log with drm.debug and printk.time enabled:
>  > Uncompressed (22M): http://files.hz6.de/kern_20130722.log
>
> These logs show that interrupts are still coming thru although they
> should be disabled.

Hm, in my reading of that logfile it looks like the irq disabling
works, every time we detect a storm there's no noise for 2 minutes on
that pin. But it seems to take the code an awful long time to notice a
storm, sometimes it even takes 2-3 minutes ... And we seem to get a
lot of hpd events per second, so this should trigger much quicker. No
idea yet what's going on here.
-Daniel
--
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch