From mboxrd@z Thu Jan 1 00:00:00 1970 From: "Antonino A. Daplas" Subject: Sane behavior of fbset Date: Fri, 18 Jun 2004 09:45:12 +0800 Sender: linux-fbdev-devel-admin@lists.sourceforge.net Message-ID: <200406180945.12444.adaplas@hotpop.com> Reply-To: adaplas@pol.net 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 1Bb8Qd-0000OI-6k for linux-fbdev-devel@lists.sourceforge.net; Thu, 17 Jun 2004 18:44:27 -0700 Received: from babyruth.hotpop.com ([38.113.3.61]) by sc8-sf-mx1.sourceforge.net with esmtp (Exim 4.30) id 1Bb8Qc-00023Z-OO for linux-fbdev-devel@lists.sourceforge.net; Thu, 17 Jun 2004 18:44:26 -0700 Received: from hotpop.com (kubrick.hotpop.com [38.113.3.103]) by babyruth.hotpop.com (Postfix) with SMTP id 738A8618B28 for ; Fri, 18 Jun 2004 01:05:59 +0000 (UTC) Received: from 203.177.116.25 (unknown [203.177.116.25]) by smtp-1.hotpop.com (Postfix) with ESMTP id 58D011A01AC for ; Fri, 18 Jun 2004 00:43:44 +0000 (UTC) Content-Disposition: inline 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 development list Hi, Currently, using fbset either corrupts the display, or at worst, hangs the GPU. I consider this a critical bug. I don't want to discuss the pros/cons of using fbset vs stty to change the console size, but we need to make sure that using fbset (or any utility that utilizes the fb_set_var ioctl) does not produce undefined behavior. There are at least 3 possibilities: 1. Revert to 2.4 behavior. This is easy to add since fbdev already has a notifier support. (I already have working code for this). Of course, stty will still work. 2. Make the set_var ioctl return immediately if the vc_mode of the current display is KD_TEXT. Basically, fbset becomes an informational utility only. I don't know the repercussions of this with userland fb applications though. 3. Modify fbset (and other similar utilities, if there are any) so it also issues an 'stty-like' call after a 'set_var' call. Note: As mentioned by many people before, it's almost impossible to completely preserve per-console mode info because of the lack of a per-display var. So even if we agree to implement #1, it cannot completely match 2.4 behavior. Also, the lack of per-display var means that drivers must be able to handle mode changes without any help. James' fb_find_mode support in fbcon_resize does partly alleviate this limitation. Comments? Tony ------------------------------------------------------- This SF.Net email is sponsored by The 2004 JavaOne(SM) Conference Learn from the experts at JavaOne(SM), Sun's Worldwide Java Developer Conference, June 28 - July 1 at the Moscone Center in San Francisco, CA REGISTER AND SAVE! http://java.sun.com/javaone/sf Priority Code NWMGYKND