From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ville =?iso-8859-1?Q?Syrj=E4l=E4?= <ville.syrjala@linux.intel.com>
Subject: Re: [RFC][PATCH 1/1] drm/i915: Rewrite ILK+ watermark
 handling
Date: Fri, 10 May 2013 10:14:18 +0300
Message-ID: <20130510071418.GT14974@intel.com>
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To: Jesse Barnes <jbarnes@virtuousgeek.org>
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On Thu, May 09, 2013 at 12:09:30PM -0700, Jesse Barnes wrote:
> On Mon,  6 May 2013 16:45:52 +0300
> ville.syrjala@linux.intel.com wrote:
> =

> > From: Ville Syrj=E4l=E4 <ville.syrjala@linux.intel.com>
> > =

> > Rewrite the ILK+ watermark code to allow:
> > - updating the watermarks safely (to avoid underruns)
> > - pre-computing watermarks (will help with atomic modest and pageflip)
> > - enabling LP1+ watermarks for HSW multi-pipe scenarios
> =

> This looks like the right way to go long term.  But Paulo's patches for
> HSW are fairly small and make things better immediately, so we should
> probably get them in first.

Agreed. I'll try to review them properly soon, so far I just glanced at
them.

> This one needs to be split up somehow so we can review it better like
> you mention in the TODO.
> =

> Another thing that I used when doing the WM code way back when was to
> port it to userspace and run through various configs to make sure the
> values were all sane.  Might be nice if we could do that easily
> somehow, maybe with an #ifdef or putting all the wm stuff into a
> separate file.

Actually I had this stuff running in user space first :)

It's not that hard to implement the required stubs to get some drm
file to compile in userland. I did it already for drm_edid.c (stuff
that I've neglected to publish anywhere). I've not tried it for i915
code, and I suppose it may be a bit more work. Splitting the watermark
stuff into a separate file could help a bit though.

-- =

Ville Syrj=E4l=E4
Intel OTC