[Intel-gfx] [PATCH 02/11] drm/i915: Clarify event_lock locking, irq&mixed context

[Daniel Vetter]

On Mon, Sep 29, 2014 at 02:20:27PM +0800, Jike Song wrote:
> On 09/15/2014 08:55 PM, Daniel Vetter wrote:
> >Now we tackle the functions also called from interrupt handlers.
> >
> >- intel_check_page_flip is exclusively called from irq handlers, so a
> >   plain spin_lock is all we need. In i915_irq.c we have the convention
> >   to give all such functions an _irq_handler postfix, but that would
> >   look strange and als be a bit a misleading name. I've opted for a
> >   WARN_ON(!in_irq()) instead.
> 
> Hi Daniel,
> 
>  Is it possible to use in_interrupt() instead? Sorry to tell that, in
> our iGVT-g implementation, the host i915 irq handler needs to be called
> in a non hardirq driven context. i.e. a tasklet or workqueue.

Hm, why that? Depending upon how you do this you might break a lot of the
interrupt related locking we have ... This is a crucial integration issue,
which patch does that change?
-Daniel
-- 
Daniel Vetter
Software Engineer, Intel Corporation
+41 (0) 79 365 57 48 - http://blog.ffwll.ch