From mboxrd@z Thu Jan 1 00:00:00 1970 From: Knut Petersen Subject: [BUG] Strange interaction between X and /dev/fb0 + /dev/fb1 Date: Sun, 31 Jul 2005 07:18:09 +0200 Message-ID: <42EC5F11.2070606@t-online.de> Reply-To: linux-fbdev-devel@lists.sourceforge.net Mime-Version: 1.0 Content-Transfer-Encoding: quoted-printable Return-path: Received: from sc8-sf-mx1-b.sourceforge.net ([10.3.1.91] helo=mail.sourceforge.net) by sc8-sf-list1.sourceforge.net with esmtp (Exim 4.30) id 1Dz6Bq-00005A-WF for linux-fbdev-devel@lists.sourceforge.net; Sat, 30 Jul 2005 22:16:47 -0700 Received: from mailout11.sul.t-online.com ([194.25.134.85]) by mail.sourceforge.net with esmtp (Exim 4.44) id 1Dz6Bq-0004Vj-Il for linux-fbdev-devel@lists.sourceforge.net; Sat, 30 Jul 2005 22:16:46 -0700 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="iso-8859-1"; format="flowed" To: linux-fbdev-devel@lists.sourceforge.net Hi everybody, 1: the system boots with video=3Dvesafb:ypan 2: cyblafb is loaded by the boot.local script 3: con2vt /dev/fb1 /dev/tty1 4: runlevel 3 (no X) is used As cyblafb detects the video mode used by vesafb, everything works fine. If I switch to tty1, the accelerated cyblafb driver is used, all ot= her ttys use the slow vesafb code. I can unload cyblafb after a con2ct /dev/fb0 /dev/tty1, load it again,=20 switch between ttys, everything without a problem. Now I switch to runlevel 5. 1: Switching from X to any tty, no matter if it is managed by vesafb or cyblafb,does work without problems. 2: Switching from any tty to X works without a problem. 3: Switching from X to any tty except tty1 (managed by cyblafb) and then between any ttys works without problems. 4: Switching from X to tty1 and then to any other tty does _not_ work. The cursor stops blinking, otherwise nothing changes on the monitor. Blindly entered commands produce no visible output, but they are executed. 5: Switching to X and then back to the "dead" tty solves the problem. Output of the blindly run command is now visible, but scrolling took place only on the last line of the screen. Everything works fine as long as I do not repeat step 4 ;-) 2.6.12 and 2.6.13-rc4 behave identical. As everything works without X, I do believe that there is no bug in the framebuffer drivers involved. This is not a problem of programming some hardware registers. Loading two framebuffer drivers for one chip is a hack that is usefull for devopement and debuging, it=B4s nothing a real user would do. We coul= d=20 silently ignore this problem as there is an easy workaround. But the upper layers see nothing but two different framebuffer drivers ... and this should be handled correctly. cu, Knut ------------------------------------------------------- SF.Net email is sponsored by: Discover Easy Linux Migration Strategies from IBM. Find simple to follow Roadmaps, straightforward articles, informative Webcasts and more! Get everything you need to get up to speed, fast. http://ads.osdn.com/?ad_id=3D7477&alloc_id=3D16492&op=3Dclic= k