From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Antonino A. Daplas" Subject: Re: Reworking sysfs attributes for fbdev Date: Wed, 16 Mar 2005 04:27:04 +0800 Message-ID: <200503160427.04940.adaplas@hotpop.com> References: <200503111331.41352.ajax@nwnk.net> <200503151449.59874.adaplas@hotpop.com> Reply-To: linux-fbdev-devel@lists.sourceforge.net Mime-Version: 1.0 Content-Transfer-Encoding: 7bit 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 1DBIdP-00081H-GW for linux-fbdev-devel@lists.sourceforge.net; Tue, 15 Mar 2005 12:27:23 -0800 Received: from smtp-out.hotpop.com ([38.113.3.71]) by sc8-sf-mx1.sourceforge.net with esmtp (Exim 4.41) id 1DBIdN-0007pL-PM for linux-fbdev-devel@lists.sourceforge.net; Tue, 15 Mar 2005 12:27:23 -0800 Received: from hotpop.com (kubrick.hotpop.com [38.113.3.103]) by smtp-out.hotpop.com (Postfix) with SMTP id 0838314AE91A for ; Tue, 15 Mar 2005 20:27:07 +0000 (UTC) In-Reply-To: Content-Disposition: inline Sender: linux-fbdev-devel-admin@lists.sourceforge.net 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: linux-fbdev-devel@lists.sourceforge.net, Geert Uytterhoeven Cc: Jon Smirl , dri-egl@lists.freedesktop.org On Tuesday 15 March 2005 16:55, Geert Uytterhoeven wrote: > On Tue, 15 Mar 2005, Antonino A. Daplas wrote: > > On Tuesday 15 March 2005 11:43, Jon Smirl wrote: > > > Some discussion on the dri-egl list points out that the new mode > > > setting sysfs attributes for fbdev are too limited. Below is a > > > proposal I made on the dri-egl list. > > > > > > To implement this for fbdev I need to know the right set of of > > > attribute value pairs. Some obvious ones are: > > > > > > name=string > > > width=number > > > height=number > > > depth=number > > > refresh=number > > > interlace= yes | no | double > > > type = detailed|standard|vesa|user > > > sync = horizonatal_high | vertical_high | external | composite | > > > broadcast | green > > > left=number > > > right=number > > > lower=number > > > upper=number > > > hsync=number > > > vsync=number > > > pixclock=number > > > > > > Right now fb0/modes is set by passing in an array of fb_videomode > > > structs. To convert this to attribute value pair I needs the full set > > > so that no info is lost. > > > > > > If the mode and depth are independent variables we can end up with a > > > combo that exceeds monitor or hardware bandwidth. Would it be better > > > to combine the depth into the modes list? or if you try to set a > > > > We can do that, vesa's mode id's are like that. Although I prefer that > > mode setting should be separated from the framebuffer format setting (ie, > > depth), it's currently difficult to make this work safely the reason > > being that not all check_var() functions can be relied upon. > > So should we separate into geometry, timings, visual (cfr. fbutils)? Ideally, yes, but the problem with fbsysfs is that a regular user can change the mode. Once we do the separation, combinations will exist that can be illegal. ie echo 1024x768@60 > fb0/mode echo 32 > fb0/depth The second set may not be compatible with the preceeding one. Although drivers do have a check_var(), I don't think all are robust enough to screen out illegal combinations. Tony ------------------------------------------------------- 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