From mboxrd@z Thu Jan 1 00:00:00 1970 From: Bruno Ducrot Subject: Re: ACPI C4 support Date: Mon, 1 Mar 2004 20:39:17 +0100 Sender: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org Message-ID: <20040301193917.GA2869@poupinou.org> References: <20040301192738.GA9459@elf.ucw.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Return-path: Content-Disposition: inline In-Reply-To: <20040301192738.GA9459-I/5MKhXcvmPrBKCeMvbIDA@public.gmane.org> Errors-To: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , List-Archive: To: Pavel Machek Cc: "Grover, Andrew" , Stefan Behlert , ACPI mailing list , trenn-l3A5Bk7waGM@public.gmane.org, "Brown, Len" List-Id: linux-acpi@vger.kernel.org On Mon, Mar 01, 2004 at 08:27:38PM +0100, Pavel Machek wrote: > Hi! > > > > [mailto:acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@public.gmane.org] On Behalf Of > > > Stefan Behlert > > > > No. pblk_length is 0 or 6. Not 5 nor 7 ;) > > > > > > Sorry, I don't understand: We've a Laptop with a DSDT with > > > Processor (\_PR.CPU0, 0x01, 0x00001010, 0x07) > > > in it. > > > Comment from the responsible BIOS-team: > > > "Our processor block object is 7 bytes in length because we > > > also support > > > C4 (P_LVL4) which is at +6. Therefore, the > > > size/length must be > > > reported as 7 and not 6." > > > > > > Is the '7' the BIOS-developer mentioned the same '7' as > > > mentioned by you? > > > > This is wrong. > > > > There is confusion here because what older systems do on C3 is different > > from what more recent systems do on C3, at the electrical level. I know > > at least internally the improved C3-like state was called "C4" but to > > the OS it just looks just like C3, and the value for C4 should go in > > P_LVL3. P_BLK length should remain 6. > > > > The only way to get more than C1, C2, and C3 is via the _CST object. > > > > Please tell the BIOS developer this. I have an old BIOS developers guide > > version that agrees with them but I just asked the experts internally > > and they said no. > > If there is old BIOS guide telling them to use length of 7, could we > make Linux accept that? Its likely a lot of developers have read > that... > > Allowing length of 7 is one line change; if we do it, such notebooks > will be able to use C1..C3, but not C4. That does not seem too bad... > The problem is that, from strict acpi point of view, it will be too easy to allow '7', and _CST support is much better. Don't ask me why, I'm not an expert. So perhaps it may be possible to add the (bahh, beurk) length of 7 if there exist a bad written bios developper guide released apparently by Intel, at least as a non pedantic acpi option? -- Bruno Ducrot -- Which is worse: ignorance or apathy? -- Don't know. Don't care. ------------------------------------------------------- SF.Net is sponsored by: Speed Start Your Linux Apps Now. Build and deploy apps & Web services for Linux with a free DVD software kit from IBM. Click Now! http://ads.osdn.com/?ad_id=1356&alloc_id=3438&op=click