From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin Herrenschmidt Subject: Re: [PATCH] Fix switch from XFree Date: Tue, 10 Feb 2004 22:17:21 +1100 Sender: linux-fbdev-devel-admin@lists.sourceforge.net Message-ID: <1076411840.874.18.camel@gaston> References: <1076409397.873.6.camel@gaston> <20040210110622.GA1913@lambda> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.11] helo=sc8-sf-mx1.sourceforge.net) by sc8-sf-list1.sourceforge.net with esmtp (Exim 4.30) id 1AqVtZ-0004Jz-5U for linux-fbdev-devel@lists.sourceforge.net; Tue, 10 Feb 2004 03:17:37 -0800 Received: from gate.crashing.org ([63.228.1.57] ident=root) by sc8-sf-mx1.sourceforge.net with esmtp (TLSv1:AES256-SHA:256) (Exim 4.30) id 1AqVte-0005V4-IQ for linux-fbdev-devel@lists.sourceforge.net; Tue, 10 Feb 2004 03:17:42 -0800 In-Reply-To: <20040210110622.GA1913@lambda> Errors-To: linux-fbdev-devel-admin@lists.sourceforge.net List-Unsubscribe: , List-Id: List-Post: List-Help: List-Subscribe: , List-Archive: Content-Type: text/plain; charset="us-ascii" To: Sven Luther Cc: James Simmons , Linux Fbdev development list > Mmm, i wonder about this. The X driver is supposed to be responsible for > saving and reseting the engine when leaving/entering. This is usually > done in a separate way when using or not using fbdev. This is a nice dream. It's both _very_ impractical (you can't always _read_ the engine state) and usually buggy as hell (and go fix XFree :) On the other hand, it's very simple for the driver to just reset & restore the engine state it expects. > Now, if we are going to save/restore the contect too, then this would > mean a risk of dual saving the engine state. Or maybe the X server > doesn't really save the context, but just reinitialize it when entering. It tries too for the mode... but fails. It doesn't try for the engine > I have the feeling that more working together would be helpfull, or > maybe setup a proper policy for X/fbdev to handle this properly. I don't think it's reasonable to expect the XFree driver to save/restore the accel engine state. It's already quite broken with the mode on radeonfb (the VGA stuff seem to do bad things on PPC at least). > Maybe the fbdev driver could set a flag or something, which would tell > the X server that it is taking charge of saving/restoring the accel > engine, so the X driver would not try doing this too, at least in the > UseFBDev case (but do we care about the other case ?). No. Trying to save/restore the engine state would mean trying to save/restore dozens (or hundreds maybe ? depends if you count the 3D engine too :), it makes little sense, it's much simpler for fbdev to just reset the state it expects. Ben. ------------------------------------------------------- The SF.Net email is sponsored by EclipseCon 2004 Premiere Conference on Open Tools Development and Integration See the breadth of Eclipse activity. February 3-5 in Anaheim, CA. http://www.eclipsecon.org/osdn