From mboxrd@z Thu Jan 1 00:00:00 1970 From: Kevin Hilman Subject: Re: Use of 'reserved' fields in var_screeninfo Date: Mon, 14 Nov 2005 11:46:31 -0800 Message-ID: <4378E997.50208@mvista.com> References: <4378E2CB.3080902@mvista.com> Reply-To: linux-fbdev-devel@lists.sourceforge.net Mime-Version: 1.0 Content-Transfer-Encoding: 7bit Return-path: Received: from sc8-sf-mx2-b.sourceforge.net ([10.3.1.92] helo=mail.sourceforge.net) by sc8-sf-list1.sourceforge.net with esmtp (Exim 4.30) id 1EbkHi-0002O1-VJ for linux-fbdev-devel@lists.sourceforge.net; Mon, 14 Nov 2005 11:46:34 -0800 Received: from gateway-1237.mvista.com ([12.44.186.158] helo=hermes.mvista.com) by mail.sourceforge.net with esmtp (Exim 4.44) id 1EbkHh-0003vM-SV for linux-fbdev-devel@lists.sourceforge.net; Mon, 14 Nov 2005 11:46:35 -0800 Received: from [127.0.0.1] (godzilla.mvista.com [10.0.0.2]) by hermes.mvista.com (Postfix) with ESMTP id 472711A6F1 for ; Mon, 14 Nov 2005 11:46:32 -0800 (PST) In-Reply-To: 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 wrote: > On Mon, 14 Nov 2005, Kevin Hilman wrote: > >>I've got a question about the purpose of the reserved fields in the >>var_screeninfo struct: >> >>struct fb_var_screeninfo { >> [ ... ] >> __u32 reserved[5]; /* Reserved for future compatibility */ >>}; >> >>What are these reserved for? Is it appropriate for drivers to use these for > > > They are reserved for future expansion. > > >>additional, HW-specific values that are then made available to the VSCREENINFO >>ioctls? > > > Not really, only for generic info that's useful for multiple drivers. > What do you want to export there? > I'm just weighing the options of whether I should just add a new device-specific ioctl, or try to export this as part of the var_screeninfo. I've got some HW which has the ability display/blend up to 4 video/graphics sources within a root display window. I'd like to export this x,y offset (which is independent of the xoffset,yoffset for the virtual/visual stuff). Also, it has a per-source scaling factor I'd like to export. Kevin ------------------------------------------------------- SF.Net email is sponsored by: Tame your development challenges with Apache's Geronimo App Server. Download it for free - -and be entered to win a 42" plasma tv or your very own Sony(tm)PSP. Click here to play: http://sourceforge.net/geronimo.php