From mboxrd@z Thu Jan 1 00:00:00 1970 From: Benjamin Herrenschmidt Subject: Re: [PATCH 2/6] fbcon: Stop framebuffer operations before hardware is properly initialized Date: Mon, 14 Mar 2005 10:07:15 +1100 Message-ID: <1110755235.5787.189.camel@gaston> References: <200503130833.44469.adaplas@hotpop.com> Reply-To: linux-fbdev-devel@lists.sourceforge.net Mime-Version: 1.0 Content-Transfer-Encoding: 7bit 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 1DAcBu-00022n-U6 for linux-fbdev-devel@lists.sourceforge.net; Sun, 13 Mar 2005 15:08:10 -0800 Received: from gate.crashing.org ([63.228.1.57]) by sc8-sf-mx2.sourceforge.net with esmtp (TLSv1:AES256-SHA:256) (Exim 4.41) id 1DAcBt-00072q-De for linux-fbdev-devel@lists.sourceforge.net; Sun, 13 Mar 2005 15:08:10 -0800 In-Reply-To: <200503130833.44469.adaplas@hotpop.com> 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 development list Cc: Andrew Morton On Sun, 2005-03-13 at 08:33 +0800, Antonino A. Daplas wrote: > Accessing the hardware before it is properly initialized can lead to crashes > or screen corruption. This happens when switching to X then back to console. > When console comes back from X, the device is in an undefined state. During > this window, accessing the hardware is disallowed. > > A new field in fbcon_par is added (graphics), which will be set to nonzero > just before initialization of the framebuffer and when coming back from > KD_GRAPHICS, then unset when an fb_set_var/fb_set_par is done. While this > field is set, no accesses to the hardware is done. The consequence of > this change is, hopefully, more robust switching between KD_GRAPHICS<-> > KD_TEXT. > > An added benefit coming from this change is that the MODESWITCHLATE hack > is not needed anymore and thus removed. This hack is used by savagefb, > rivafb and nvidiafb. Excellent ! That should fix some nasty issues I've been dealing with as well ! Ben. ------------------------------------------------------- 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