[Intel-gfx] [PATCH 1/2] drm/i915: Move engine reset preparation to i915_gem_reset_prepare()

[Mika Kuoppala]

Chris Wilson <chris at chris-wilson.co.uk> writes:

> On Mon, Jan 16, 2017 at 04:03:16PM +0200, Mika Kuoppala wrote:
>> Chris Wilson <chris at chris-wilson.co.uk> writes:
>> 
>> > Now that we have prepare/finish routines for the GEM reset, move the
>> > disabling of the engine->irq_tasklet into them to reduce repetition. The
>> > device irq enable/disable is split out to ensure it is run first and
>> > last always (even if the GPU reset fails).
>> >
>> > Signed-off-by: Chris Wilson <chris at chris-wilson.co.uk>
>> > Cc: Mika Kuoppala <mika.kuoppala at intel.com>
>> 
>> As discussed briefly in irc, the disabling could be part of
>> reset and enabling part of init_hw, that way we could wedge
>> also with irq's off, even if it breaks the symmetry.
>
> We can't leave the irq off when wedged. It's the device IRQ, so hotplug,
> gmbus and all sorts of transactions, not just our own user +
> context-switch interrupts. Did you have something else in mind?

Ah yes indeed that would be nasty for the display side. I was thinking
that reset and whole hw init while irqs are off would be safer or
more controlled.

-Mika

> -Chris
>
> -- 
> Chris Wilson, Intel Open Source Technology Centre