From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin Herrenschmidt Subject: Re: fbcon VT (mode) switching issue Date: Wed, 28 Apr 2004 10:44:02 +1000 Sender: linux-fbdev-devel-admin@lists.sourceforge.net Message-ID: <1083113041.20092.17.camel@gaston> References: <10040.159.37.7.44.1083099594.squirrel@www.foogod.com> Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.12] helo=sc8-sf-mx2.sourceforge.net) by sc8-sf-list1.sourceforge.net with esmtp (Exim 4.30) id 1BIdGp-0000Bb-OC for linux-fbdev-devel@lists.sourceforge.net; Tue, 27 Apr 2004 17:49:51 -0700 Received: from gate.crashing.org ([63.228.1.57] ident=root) by sc8-sf-mx2.sourceforge.net with esmtp (TLSv1:AES256-SHA:256) (Exim 4.30) id 1BIdGp-0002NW-9q for linux-fbdev-devel@lists.sourceforge.net; Tue, 27 Apr 2004 17:49:51 -0700 In-Reply-To: <10040.159.37.7.44.1083099594.squirrel@www.foogod.com> 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: Alex Stewart Cc: Linux Fbdev development list > This appears to be due to the fact that when changing VTs, set_par (which > is where neofb changes the hardware video mode) isn't called until > sometime after the fbcon code uses imageblit to transfer the console text > to the screen. The result is that the accelerated imageblit is done with > the hardware still set to the old screen resolution/depth, and thus the > neomagic chip writes the data to memory in a form appropriate for the old > mode, not the new one that we're switching to. That's weird, we should get a call to fbcon_blank() triggering an FB_ACTIVATE_FORCE call before anything is drawn (on the switch from KD_GRAPHICS to KD_TEXT more specifically). > I've tried to figure out how this whole process works and what the best > fix for this problem is, but to be honest, trying to follow some of the > code paths in the framebuffer console system is rather like trying to > follow Brer Rabbit through the briar patch.. I could use the help of > somebody a bit more familiar with this part of things, I think. > > I have determined that adding a call to set_par at the beginning of > fbcon_switch does fix the problem. Of course it also ends up calling > set_par twice during the overall switching procedure (with noticeable > flicker), and I'm not really sure this is the right place to put it > anyway, so I wanted to get people's opinion as to what the right fix is.. That's not the right fix. Ben. ------------------------------------------------------- This SF.Net email is sponsored by: Oracle 10g Get certified on the hottest thing ever to hit the market... Oracle 10g. Take an Oracle 10g class now, and we'll give you the exam FREE. http://ads.osdn.com/?ad_id=3149&alloc_id=8166&op=click