From mboxrd@z Thu Jan 1 00:00:00 1970 From: ebiederm-aS9lmoZGLiVWk0Htik3J/w@public.gmane.org (Eric W. Biederman) Subject: Re: [RFC] Reliable video POSTing on resume (was: Re: Samsung P35, S3, black screen (radeon)) Date: 07 Feb 2005 12:27:41 -0700 Message-ID: References: <420217DB.709@gmx.net> <4202A972.1070003@gmx.net> <20050203225410.GB1110@elf.ucw.cz> <1107474198.5727.9.camel@desktop.cunninghams> <4202DF7B.2000506@gmx.net> <1107485504.5727.35.camel@desktop.cunninghams> <9e4733910502032318460f2c0c@mail.gmail.com> <20050204074454.GB1086@elf.ucw.cz> <9e473391050204093837bc50d3@mail.gmail.com> <20050205093550.GC1158@elf.ucw.cz> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20050205093550.GC1158-I/5MKhXcvmPrBKCeMvbIDA@public.gmane.org> Sender: acpi-devel-admin-5NWGOfrQmneRv+LV9MX5uipxlwaOVQ5f@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: Jon Smirl , ncunningham-jjFNsPSvq+iXDw4h08c5KA@public.gmane.org, Carl-Daniel Hailfinger , ACPI List , Linux Kernel Mailing List List-Id: linux-acpi@vger.kernel.org Pavel Machek writes: > Hi! > > > > We already try to do that, but it hangs on 70% of machines. See > > > Documentation/power/video.txt. > > > > We know that all of these ROMs are run at power on so they have to > > work. This implies that there must be something wrong with the > > environment the ROM are being run in. Video ROMs make calls into the > > INT vectors of the system BIOS. If these haven't been set up yet > > running the VBIOS is sure to hang. Has someone with ROM source and > > the appropriate debugging tools tried to debug one of these hangs? > > Alternatively code could be added to wakeup.S to try and set these up > > or dump the ones that are there and see if they are sane. > > Rumors say that notebooks no longer have video bios at C000h:0; rumors > say that video BIOS on notebooks is simply integrated into main system > BIOS. I personaly do not know if rumors are true, but PCs are ugly > machines.... The state of current hardware has already been mentioned but let me clarify. This is not a laptop problem anytime you have onboard video you are unlikely to have a separate video ROM. This includes many recent server boards as well as laptops. When the board boots up there will be a video option ROM shadowed into the usually location at C000h:0 but what becomes of it afterwards is a good question. For server boards most commonly this seems to be a flavor of the ATI Rage XL chip. It is a low end part that I doubt getting documentation for will be very hard. And according to Documentation/power/video.txt this is one of the cases that actually works. What is happening in those POST routines of a video card is typically the code to initialize the memory controller on the video card. Plus a little bit of code to set the video mode. If I read the documentation correctly in a S3 power state only the RAM is preserved. So it does look like the video post is needed. Hmm. Looking at the ACPI 3.0 spec it appears there is a _ROM method that can be called to get a copy of the ROM image for an onboard video card. Has any one tried that method? Eric ------------------------------------------------------- SF email is sponsored by - The IT Product Guide Read honest & candid reviews on hundreds of IT Products from real users. Discover which products truly live up to the hype. Start reading now. http://ads.osdn.com/?ad_id=6595&alloc_id=14396&op=click