From mboxrd@z Thu Jan 1 00:00:00 1970 From: Joakim Tjernlund Date: Thu, 24 Jan 2013 09:40:45 +0100 Subject: [U-Boot] mpc512x: Trouble migrating from 2012.07 to 2013.01 In-Reply-To: References: , <20130123212559.309ED2454A1@gemini.denx.de> Message-ID: List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Mats K?rrman wrote on 2013/01/23 22:58:56: > > Dear Wolfgang Denk, > > >> Found that it was looping endlessly in arch/powerpc/lib/ticks.S::wait_ticks > (). Reverting commit "ppc: Create a stack frame for wait_ticks()" made > everything work again. > > > > This makes no sense to me - especially as it works on all other > > systems. > Me neither, there is not a lot details. I do recall having other problems with wait_ticks from time to time, sometimes the TB counter(mtfbu, mftb in get_ticks) would not increment so one would just loop forever in wait_ticks. This problem had nothing to do with my patch though. Never got around to finding out what caused it, we ended up blaming unstable HW. Some ideas though: - Perhaps you have some alignment problem, try adding nop's here and there. - My patch uses r0(which is what one should use to make gdb happy) instead of r8 to stash the LR. Possibly you have some odd dependency on r0, try using r8 again. None of the above is a real fix tough. > If you say it works, it makes no sense to me either. I thought it might be > some subtle difference in the way the e300c4 core or GCC works compared to > other PPC cores. If there are no such differences, then a patch with no > intended functional difference beyond keeping gdb happy should not make any > difference, good or bad. hmm, we use e300c2 with no problem. Jocke