From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from metis.ext.pengutronix.de ([2001:6f8:1178:4:290:27ff:fe1d:cc33]) by casper.infradead.org with esmtps (Exim 4.76 #1 (Red Hat Linux)) id 1SKOxG-0000H9-Jo for barebox@lists.infradead.org; Wed, 18 Apr 2012 07:05:35 +0000 Date: Wed, 18 Apr 2012 09:05:17 +0200 From: Sascha Hauer Message-ID: <20120418070517.GK3852@pengutronix.de> References: <20120418004139.4bdc7da1@eb-e6520> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20120418004139.4bdc7da1@eb-e6520> List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="iso-8859-15" Content-Transfer-Encoding: quoted-printable Sender: barebox-bounces@lists.infradead.org Errors-To: barebox-bounces+u.kleine-koenig=pengutronix.de@lists.infradead.org Subject: Re: 800x480 Display broken on i.MX25 with MMU To: Eric =?iso-8859-15?Q?B=E9nard?= Cc: barebox@lists.infradead.org On Wed, Apr 18, 2012 at 12:41:39AM +0200, Eric B=E9nard wrote: > Hi, > = > on an i.MX25, it seems that 3100ea14668853aeedae85ec83e3536b59ba7728 > broke framebuffer usage with a 800x480 display when MMU is enabled : > about 1/4 of the display (at the bottom) is garbage. > = > v2011.08.0 : it works fine > = > v2011.09.0 : it fails > = > disabling MMU makes it work again in v2011.09.0 > = > then in v2011.09.0 it works with MMU enabled after reverting the > following commits : > 43ebdba64a6e1c12fe58aa57e905cfdcef922126 > 56c379160b9f0b52efcaaefce9adb6121d5865d7 > a6c333c7f2dbe49189dd5343da3c921659e88cbf > 3100ea14668853aeedae85ec83e3536b59ba7728 > = > So it seems something was broken during MMU rework and I don't yet know > what : Sascha do you have an idea ? What is the address of your framebuffer memory? The LCDC has a nasty limitation, the DMA controller can only access 4MB, the other address lines are fix. This means that you can't cross a 4MB boundary with the framebuffer. Currently this case is not caught anywhere. Sascha -- = Pengutronix e.K. | | Industrial Linux Solutions | http://www.pengutronix.de/ | Peiner Str. 6-8, 31137 Hildesheim, Germany | Phone: +49-5121-206917-0 | Amtsgericht Hildesheim, HRA 2686 | Fax: +49-5121-206917-5555 | _______________________________________________ barebox mailing list barebox@lists.infradead.org http://lists.infradead.org/mailman/listinfo/barebox