From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alan Hourihane Subject: Re: Atari TT (next) Date: Sun, 08 Jan 2012 23:59:12 +0000 Message-ID: <4F0A2DD0.4000707@fairlite.co.uk> References: <4F079F6B.8080502@fairlite.co.uk> <4F07EA66.6020603@gmail.com> <4F08E748.4020305@fairlite.co.uk> <4F0917E9.9090600@gmail.com> <4F0964EC.2080505@fairlite.co.uk> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Return-path: Received: from fairlite.demon.co.uk ([80.176.228.186]:56086 "EHLO fairlite.demon.co.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754738Ab2AHX7P (ORCPT ); Sun, 8 Jan 2012 18:59:15 -0500 In-Reply-To: Sender: linux-m68k-owner@vger.kernel.org List-Id: linux-m68k@vger.kernel.org To: Michael Schmitz Cc: Linux/m68k , Geert Uytterhoeven On 08/01/12 23:51, Michael Schmitz wrote: > Hi Alan, > >>> Come to think of it - does the TT video chipset actually require >>> screen memory to reside in ST-RAM? If it's fully 32 bit addressed we >>> should not have any problems with TT-RAM. The problems you see might >>> be caused by a fault in the TT codepath in atafb - I'm unsure this has >>> been tested since the last atafb rewrite. >> Looking at atafb, we always allocate FB memory from STRAM unless it's an >> external video card, i.e. VME, ISA etc. > That's right - but in your case ST-RAM is not being mapped at all so > it can't be used. You will get a chunk of TT-RAM assigned to atafb > (fallback in case there's no more ST-RAM), the framebuffer code will > happily draw there but the shifter cannot access it. I understand, but the STRAM allocator is broken. It gives out TT-RAM. It should never do that on a TT. >>> Can you try to have the kernel placed in ST-RAM? >> No, the kernel is too big. I've only got 4MB ST-RAM. And getting more on >> the TT is pretty rare as the only other option is 10MB using the onboard >> 2MB and an 8MB upgrade board. > You may have to pare the kernel down to the bare minimum (i.e. > modularize about everything you don't need to boot to initrd). Not > sure where the limit for this is these days. Already tried that. Still too big, because we need buffers from STRAM too. >>> You're right, this should be possible to test with ARAnyM - the >>> behavior is not new though. Loading the kernel in TT-RAM has been >>> problematic on the Falcon for a long time now. >> Sure, but by default Falcon's have only 4MB ST-RAM too, and yes lots of >> people have 14MB of ST-RAM now, but it's not uncommon to have 4MB ST-RAM. > I think my Falcon is the only machine kernels have been tested on in > the last few years - I've got 14MB ST-RAM so I was never affected. I > had played with getting the kernel run in TT-RAM briefly but MM is not > my strong suit so I never got anywhere. > >> I'll dig in. > Much appreciated. > No probs. I'll report back when I have something. Alan.