On Wed, Apr 18, 2012 at 12:41:39AM +0200, Eric Bénard 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@xxxxxxxxxxxxxxxxxxx http://lists.infradead.org/mailman/listinfo/barebox
