From mboxrd@z Thu Jan 1 00:00:00 1970 From: Pavel Machek Subject: Re: [RFC] Reliable video POSTing on resume (was: Re: Samsung P35, S3, black screen (radeon)) Date: Thu, 10 Feb 2005 20:31:23 +0100 Message-ID: <20050210193123.GC1391@elf.ucw.cz> References: <1107695583.14847.167.camel@localhost.localdomain> <420BB267.8060108@tmr.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <420BB267.8060108-sQDSfeB7uhw@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: Bill Davidsen Cc: Alan Cox , Jon Smirl , ncunningham-jjFNsPSvq+iXDw4h08c5KA@public.gmane.org, Carl-Daniel Hailfinger , ACPI List , Linux Kernel Mailing List List-Id: linux-acpi@vger.kernel.org Hi! > >>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.... > >> > > > > > >A small number of laptop systems are known to pull this trick. There are > >other problems too - the video bios boot may make other assumptions > >about access to PCI space, configuration, interrupts, timers etc. > > > >Some systems (intel notably) appear to expect you to use the bios > >save/restore video state not re-POST. > > Isn't that what it's there for? In any context other than save/restore I > wouldn't think using the BIOS was a good approach. But this is a special > case, and if there's a BIOS function which does the right thing, it > would seem to be easier to assume that the BIOS works than that the > driver can do every operation for a clean restart. > > The problem is that while POST leaves the video in a known state, it may > not the known state you want, nor is it a given that you can get from > there to where you were on suspend. PC hardware isn't always that > dependable. Eh? POST leaves video in 80x25 text mode, and we know how to handle that mode just fine... Historically that's what we ran our consoles at, so X can handle it etc. Pavel -- People were complaining that M$ turns users into beta-testers... ...jr ghea gurz vagb qrirybcref, naq gurl frrz gb yvxr vg gung jnl! ------------------------------------------------------- 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