From owner-freebsd-acpi@FreeBSD.ORG Mon Feb 2 15:50:18 2009 Return-Path: Delivered-To: freebsd-acpi@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 23EE51065673 for ; Mon, 2 Feb 2009 15:50:18 +0000 (UTC) (envelope-from rpaulo@gmail.com) Received: from mail-ew0-f21.google.com (mail-ew0-f21.google.com [209.85.219.21]) by mx1.freebsd.org (Postfix) with ESMTP id 74CDF8FC1B for ; Mon, 2 Feb 2009 15:50:16 +0000 (UTC) (envelope-from rpaulo@gmail.com) Received: by ewy14 with SMTP id 14so2453935ewy.19 for ; Mon, 02 Feb 2009 07:50:16 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=gamma; h=domainkey-signature:received:received:sender:cc:message-id:from:to :in-reply-to:content-type:content-transfer-encoding:mime-version :subject:date:references:x-pgp-agent:x-mailer; bh=0ruxGDeTgAML6kukbqdyb+Abz3UgkuNNA6E5mj44uvU=; b=baNVHk9B/FpDvtRwvD6Tb3iOvgoYrncjK3cDAqy/uhdkvjJgxLz36ER7xullbls7Cm PNIo8PvRRH1Hv/vqvvuod0UqapOuarClyHFTn1AUwHQyGDzI2glOgV3JXIKc+IN4qEa9 7aFLvn0Gv+yjNo4615ZfhR9hslecLGFlSWF00= DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=gamma; h=sender:cc:message-id:from:to:in-reply-to:content-type :content-transfer-encoding:mime-version:subject:date:references :x-pgp-agent:x-mailer; b=O1IEwLiX3kQIhfggLoO9zcyfOGeNJsjGfpY+cI6Rd5F4c1DMbOUIa1p/wpg7Z9F0HQ 5dHO+kc4HmwXgnn+j/i7toz8imsEcvYEhMcymyPxpbEu1Z8rDwoczrKoy7YZrVmp8B5S 6tJdopynstxgpwh6nC0O04ve2eQTOexpsxbtQ= Received: by 10.210.111.4 with SMTP id j4mr1026054ebc.1.1233589816032; Mon, 02 Feb 2009 07:50:16 -0800 (PST) Received: from epsilon.lan ([83.144.140.27]) by mx.google.com with ESMTPS id 28sm4143844eye.59.2009.02.02.07.50.14 (version=TLSv1/SSLv3 cipher=RC4-MD5); Mon, 02 Feb 2009 07:50:15 -0800 (PST) Sender: Rui Paulo Message-Id: <66885316-6F5B-4C56-BFE0-DBB86E050C99@freebsd.org> From: Rui Paulo To: Andriy Gapon In-Reply-To: <498708FD.9030404@icyb.net.ua> Content-Type: multipart/signed; protocol="application/pgp-signature"; micalg=pgp-sha1; boundary="Apple-Mail-4--267949195" Content-Transfer-Encoding: 7bit Mime-Version: 1.0 (Apple Message framework v930.3) Date: Mon, 2 Feb 2009 15:50:04 +0000 References: <498708FD.9030404@icyb.net.ua> X-Pgp-Agent: GPGMail 1.2.0 (v56) X-Mailer: Apple Mail (2.930.3) Cc: freebsd-acpi@FreeBSD.org Subject: Re: piix4 and C2: patch for BRLD_EN_BM/ACPI_BITREG_BUS_MASTER_RLD X-BeenThere: freebsd-acpi@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: ACPI and power management development List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 02 Feb 2009 15:50:18 -0000 This is an OpenPGP/MIME signed message (RFC 2440 and 3156) --Apple-Mail-4--267949195 Content-Type: text/plain; charset=US-ASCII; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit On 2 Feb 2009, at 14:53, Andriy Gapon wrote: > > Another patch for acpi_cpu code related to PIIX4 chipset. > > We do not support C3 with this chipset and as such we never touch > ACPI_BITREG_BUS_MASTER_RLD when running on it. It's also possible > (probable) that we never reset ACPI_BITREG_BUS_MASTER_STATUS > (because of > CPU_QUIRK_NO_BM_CTRL). > So, if BIOS configures ACPI_BITREG_BUS_MASTER_RLD to 1 and > ACPI_BITREG_BUS_MASTER_STATUS gets set to 1, we would get a situation > where the system would always immediately break out of C2 state should > we ever attempt to enter it. > > Actually, ACPI spec says that bus master activity need not break out > of > C2 state (only interrupts must do that). > > Given all of the above, it seems to be safe and desired to reset > ACPI_BITREG_BUS_MASTER_RLD to zero with this chipset. > > The patch is successfully tested on a real system that exhibited the > above behavior (immediate backout from cx_lowest of C2 to C1). Looks ok to me. I no longer have a PIIX4 system to test it, though. So, if no one raises any objection, I'll commit it to HEAD in a few days. Andriy, if I forget, please ping me :-) Thanks, -- Rui Paulo --Apple-Mail-4--267949195 content-type: application/pgp-signature; x-mac-type=70674453; name=PGP.sig content-description: This is a digitally signed message part content-disposition: inline; filename=PGP.sig content-transfer-encoding: 7bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.9 (Darwin) iEYEARECAAYFAkmHFiwACgkQfD8M/ASTygJ3nwCdEYEF0BUPKYTVr5IHTyvZsTV7 01sAn234kQpWxfljbnQcWlyuYKeWZrI0 =736v -----END PGP SIGNATURE----- --Apple-Mail-4--267949195--