From mboxrd@z Thu Jan 1 00:00:00 1970 Date: Fri, 31 May 2002 17:27:56 +1000 From: David Gibson To: linuxppc-embedded@lists.linuxppc.org Subject: Re: CONFIG_PIN_TLB and telnet problems Message-ID: <20020531072756.GG16537@zax> References: <20020531071550.GF16537@zax> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii In-Reply-To: <20020531071550.GF16537@zax> Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: On Fri, May 31, 2002 at 05:15:50PM +1000, David Gibson wrote: > > Ok, I think I've managed to reproduce the telnet problems with > CONFIG_PIN_TLB that Tom Rini and others have reported. I encountered > problems telnetting to localhost on a 16MB EP405 (PVR 40110145) and on > a 32MB Walnut (PVR 401100C4). I was unable to reproduce the problem > on any of the other 405GP machines I have, each of which as at least > 64MB of RAM. > > Interestingly, if I alter the CONFIG_PIN_TLB code so that it only pins > one entry (i.e. maps 16MB of RAM instead of 32MB) I can still > reproduce the problem on the EP405, but not on the Walnut. It would > seem the problem only bites if the pinned allocation is as large or > larger than physical memory. > > It's vaguely understandable that with two pinned entries it would > break on the 16MB machine: creating a mapping for more RAM than exists > is certainly a bug. I don't yet know why there is a problem when the > mapping is exactly as large as RAM though. Update: I've now also reproduced the problem on a 64MB EP405PC board, by using mem=16M or mem=32M -- David Gibson | For every complex problem there is a david@gibson.dropbear.id.au | solution which is simple, neat and | wrong. -- H.L. Mencken http://www.ozlabs.org/people/dgibson ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/