From owner-freebsd-x11@freebsd.org Thu Mar 17 18:17:11 2016 Return-Path: Delivered-To: freebsd-x11@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 5678FAD4012 for ; Thu, 17 Mar 2016 18:17:11 +0000 (UTC) (envelope-from carpeddiem@gmail.com) Received: from mail-io0-x229.google.com (mail-io0-x229.google.com [IPv6:2607:f8b0:4001:c06::229]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "smtp.gmail.com", Issuer "Google Internet Authority G2" (verified OK)) by mx1.freebsd.org (Postfix) with ESMTPS id 30890E0F for ; Thu, 17 Mar 2016 18:17:11 +0000 (UTC) (envelope-from carpeddiem@gmail.com) Received: by mail-io0-x229.google.com with SMTP id o5so25379519iod.2 for ; Thu, 17 Mar 2016 11:17:11 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20120113; h=mime-version:sender:in-reply-to:references:from:date:message-id :subject:to:cc; bh=iCNHKUAMixFa3mdrug78OmmDwBzstpgVxqDgixZ3Zlw=; b=wzxZnYOiDGbCEMsVcUcTOsqYM2W/qztucQzNiydy2kH0PzJpuozwvbx1IXBnRY6Dio YQcldn4k98cVf8xSgKWJVUBC2MpQPPI1sMqxyycMuIlAhRgTnTMUe6RstPScUUUTfdj2 WEBMRI2DwFDmGfQOCUrZ+0x6d4L1k7C03kkuTSLbFVwKUXt2s3e6EYeOdvVqJSFBXcam t7u/K5z9B8CJjyDQLJ9PckHpbx5bfrhz3Lrcjt7N9LR8POi3+EpE3Ast2o9+Y3EXfHux sPneN4jUsHMkJOKtkCW3jsmjg3HyObm6R77oTtrwWKhGbzxzVAd/20SsF1Fh0SCVP4vI sX2w== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20130820; h=x-gm-message-state:mime-version:sender:in-reply-to:references:from :date:message-id:subject:to:cc; bh=iCNHKUAMixFa3mdrug78OmmDwBzstpgVxqDgixZ3Zlw=; b=RhlMEczyAyBLoxeBNP6lmu9Pw0LNFMLCieqH8WhTRsfwHIWhbLzo06X56vavTk/f8h ey7pUC81Ucfvx5s6rc490uKiCocmmJ4xwiFM104JQIqx8RpcqJRLe02inhrtp744VfAw CCXW452AbfttKVvTl6YxdHkkhTvnbs/p0qi9E1GfXcq2l0+edtKYS74iiPRqH/oNPBHe aInD1FxVJwsrA2I4+UhG0PjB1yE+bQudO3xWU6VPV6BbkrWMEfW51JaGORDWoc3zflvx 0MTU+auulz5nyALUeQVnB4ICpz3egDCl6UkV25H39qMyz48h6u+TBKdWf92Mn7l0rDBi LNaQ== X-Gm-Message-State: AD7BkJI9BhlTPzMJ7fRys07GAk4QTBhJ2EacFH9hLA3brBQ8Tuufzu49u1XEfN1aLuqy8kmOEKVnSNF9auP7Sg== X-Received: by 10.107.62.86 with SMTP id l83mr11419061ioa.180.1458238630516; Thu, 17 Mar 2016 11:17:10 -0700 (PDT) MIME-Version: 1.0 Sender: carpeddiem@gmail.com Received: by 10.107.39.66 with HTTP; Thu, 17 Mar 2016 11:16:50 -0700 (PDT) In-Reply-To: References: <1457974114.3576662.548762770.0E1628BF@webmail.messagingengine.com> <20160315171920.GZ1741@kib.kiev.ua> <1458086366.4068324.550308746.4DBF0576@webmail.messagingengine.com> From: Ed Maste Date: Thu, 17 Mar 2016 14:16:50 -0400 X-Google-Sender-Auth: bd7uQ_zuajAF04qY-azshasLeC4 Message-ID: Subject: Re: i915 update to Linux 3.8 ready! To: am_dxer@fastmail.fm Cc: "freebsd-x11@freebsd.org" Content-Type: text/plain; charset=UTF-8 X-BeenThere: freebsd-x11@freebsd.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: X11 on FreeBSD -- maintaining and support List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 17 Mar 2016 18:17:11 -0000 On 17 March 2016 at 11:20, Ed Maste wrote: > On 15 March 2016 at 19:59, wrote: >> >> Thank you both for the suggestions. After suspending and resuming the >> machine, I find that the power used by the GPU is significantly less. > > Thank you for testing, and I see the same behaviour on my Thinkpad > X220: after loading i915kms.ko only RC6 is nonzero and RC6+ and RC6++ > remain at zero, while after > boot RC6++ is much higher. I tried reverting the Sandy Bridge part of the change that was identified as the source of the similar problem in Linux, and it fixes the power consumption issue for me. My partial revert is just removes the write to the GEN6_MBCTL register in gen6_init_clock_gating(). Of course there's some reason it was added in Linux, but the driver was functional on Sandy Bridge and earlier hardware for years prior to the recent FreeBSD i915 update, without that register write. Thus I think it's reasonable to disable it until we either fully understand the problem or (more likely) just update to a later Linux i915 version and verify normal Sandy Bridge power consumption. The patch: https://people.freebsd.org/~emaste/D5665.diff Code review: https://reviews.freebsd.org/D5665