From mboxrd@z Thu Jan 1 00:00:00 1970 From: Chris Wilson Subject: Re: [PATCH 2/2] drm/i915: enable plain RC6 on Sandy Bridge by default Date: Fri, 23 Mar 2012 15:06:45 +0000 Message-ID: References: <1332514639-1547-1-git-send-email-eugeni.dodonov@intel.com> <1332514639-1547-3-git-send-email-eugeni.dodonov@intel.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Return-path: Received: from mga02.intel.com (mga02.intel.com [134.134.136.20]) by gabe.freedesktop.org (Postfix) with ESMTP id AA6A99E7FF for ; Fri, 23 Mar 2012 08:06:50 -0700 (PDT) In-Reply-To: <1332514639-1547-3-git-send-email-eugeni.dodonov@intel.com> List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Sender: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org Errors-To: intel-gfx-bounces+gcfxdi-intel-gfx=m.gmane.org@lists.freedesktop.org To: intel-gfx@lists.freedesktop.org Cc: Eugeni Dodonov List-Id: intel-gfx@lists.freedesktop.org On Fri, 23 Mar 2012 11:57:19 -0300, Eugeni Dodonov wrote: > This is yet another chapter in the ongoing saga of bringing RC6 to Sandy > Bridge machines by default. > > Now that we have discovered that RC6 issues are triggered by RC6+ state, > let's try to disable it by default. Plain RC6 is the one responsible for > most energy savings, and so far it haven't given any problems - at least, > none we are aware of. > > So with this, when i915_enable_rc6=-1 (e.g., the default value), we'll > attempt to enable plain RC6 only on SNB. For Ivy Bridge, the behavior > stays the same as always - we enable both RC6 and deep RC6. > > Note that while this exact patch does not has explicit tested-by's, the > equivalent settings were fixed in 3.3 kernel by a smaller patch. And it > has also received considerable testing through Canonical RC6 task-force > testing at https://wiki.ubuntu.com/Kernel/PowerManagementRC6. Up to date, > it looks like all the known issues are gone. > > v2: improve description and reference a couple of open bugs related to > RC6 which seem to be fixed with this change. > > References: https://bugs.freedesktop.org/show_bug.cgi?id=41682 > References: https://bugs.freedesktop.org/show_bug.cgi?id=38567 > References: https://bugs.freedesktop.org/show_bug.cgi?id=44867 > Signed-off-by: Eugeni Dodonov Acked-by: Chris Wilson -Chris -- Chris Wilson, Intel Open Source Technology Centre