Re: [PATCH 0/3] drm/i915: Reduce fence usage for scanout

From: Chris Wilson <chris@chris-wilson.co.uk>
To: ville.syrjala@linux.intel.com
Cc: intel-gfx@lists.freedesktop.org
Subject: Re: [PATCH 0/3] drm/i915: Reduce fence usage for scanout
Date: Tue, 28 Jan 2014 13:12:44 +0000	[thread overview]
Message-ID: <20140128131244.GQ2508@nuc-i3427.alporthouse.com> (raw)
In-Reply-To: <1390913516-730-1-git-send-email-ville.syrjala@linux.intel.com>

On Tue, Jan 28, 2014 at 02:51:53PM +0200, ville.syrjala@linux.intel.com wrote:
> From: Ville Syrjälä <ville.syrjala@linux.intel.com>
> 
> After staring at the scanout vs. fences situation a bit, I decided
> to reduce our scanout fence usage a bit.

I feel that is a glorious overreaction to a bug in another piece of
code, but now that you've done it, I can not complain. ;-)

> Ville Syrjälä (3):
>   drm/i915: Don't waste fences on sprite buffers

I suspect this is a little too generic and that there will be some
freaky old piece of hardware that requires a fence.

However, for the gen that currently use sprites, it should just work I
think. So which i-g-t hits tiled sprites?

>   drm/i915: Fix fence leaks if fbdev setup fails

If fbdev ever uses a tiled fb, I think we are in greater trouble. So
other than the leak is only a theorectical one, the patch looks sane.

>   drm/i915: Don't waste fences for scanout when not needed

But it's gen2/3 that is short of fences (and we've a... I feel this is a
micro-optimisation, but now that it is done...
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre