From mboxrd@z Thu Jan  1 00:00:00 1970
From: Daniel Vetter <daniel@ffwll.ch>
Subject: Re: [PATCH 07/11] drm/i915: Clarify irq_lock locking, irq handlers
Date: Tue, 16 Sep 2014 12:28:18 +0200
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To: Chris Wilson <chris@chris-wilson.co.uk>, Daniel Vetter <daniel.vetter@ffwll.ch>, DRI Development <dri-devel@lists.freedesktop.org>
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On Tue, Sep 16, 2014 at 11:21:52AM +0100, Chris Wilson wrote:
> On Mon, Sep 15, 2014 at 02:35:07PM +0200, Daniel Vetter wrote:
> > irq handlers always run with interrupts locally disabled, so
> > plain spinlocks is all we need. I've also reviewed again that they
> > all follow the _irq_handler postfix convention.
> 
> Hmm, we still have the full irq dance inside the reg read/write macros,
> which themselves should never be used from inside the irq handlers.
> 
> (Modulo the misgivings in execlists_irq_handler).

Hm, we still have the ACTHEAD hack to read somewhat coherent-ish seqnos.
Dunno whether open-coding that would make sense really, and whether it's
really beneficial to force register writes to never acquire forcewake from
irq context. Definitely material for different patches though.
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch