From: Chris Wilson <chris@chris-wilson.co.uk>
To: Intel Graphics Development <intel-gfx@lists.freedesktop.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Subject: Re: [PATCH] [CFT] drm/i915: Only set the down rps limit when at the loweset frequency
Date: Wed, 25 Jul 2012 23:09:42 +0100 [thread overview]
Message-ID: <1343254184_355@CP5-2952> (raw)
In-Reply-To: <1343244729-12867-1-git-send-email-daniel.vetter@ffwll.ch>
On Wed, 25 Jul 2012 21:32:09 +0200, Daniel Vetter <daniel.vetter@ffwll.ch> wrote:
> The power docs say that when the gt leaves rc6, it is in the lowest
> frequency and only about 25 usec later will switch to the frequency
> selected in GEN6_RPNSWREQ. If the downclock limit expires in that
> window and the down limit is set to the lowest possible frequency, the
> hw will not send the down interrupt. Which leads to a too high gpu
> clock and wasted power.
>
> Chris Wilson already worked on this with
>
> commit 7b9e0ae6da0a7eaf2680a1a788f08df123724f3b
> Author: Chris Wilson <chris@chris-wilson.co.uk>
> Date: Sat Apr 28 08:56:39 2012 +0100
>
> drm/i915: Always update RPS interrupts thresholds along with
> frequency
>
> but got the logic inverted: The current code set the down limit as
> long as we haven't reached it. Instead of only once with reached the
> lowest frequency.
Yup, that's different to the opposite of what I thought I was writing to
comply with the guide. :(
Note you also have to fix up intel_sanitize_pm().
-Chris
--
Chris Wilson, Intel Open Source Technology Centre
next prev parent reply other threads:[~2012-07-25 22:09 UTC|newest]
Thread overview: 8+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-07-25 19:32 [PATCH] [CFT] drm/i915: Only set the down rps limit when at the loweset frequency Daniel Vetter
2012-07-25 22:09 ` Chris Wilson [this message]
2012-07-26 9:16 ` Daniel Vetter
2012-07-26 9:23 ` Chris Wilson
2012-07-26 9:37 ` Chris Wilson
2012-07-26 9:50 ` [PATCH] drm/i915: rip out sanitize_pm again Daniel Vetter
2012-07-26 10:14 ` Chris Wilson
2012-07-26 11:38 ` Daniel Vetter
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