From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jerry Van Baren Date: Thu, 25 Aug 2005 10:40:11 -0400 Subject: [U-Boot-Users] Software watchdog on mpc8247 In-Reply-To: References: <430DAE38.2090903@smiths-aerospace.com> <430DBEC0.1080809@smiths-aerospace.com> Message-ID: <430DD84B.2070904@smiths-aerospace.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: u-boot@lists.denx.de Mike Rapoport wrote: > On 8/25/05, Jerry Van Baren wrote: > >> >>Pointing out the obvious... looking at the disassembly, it isn't >>enabling the watchdog (SWE). I'm guessing that you disassembled code >>where you had the watchdog disabled? > > > The instruction > fff031a0: 60 84 ff c3 ori r4,r4,65479 > actually enables watchdog (65479 dec = ffc7 hex) and SWE is bit 29 of SYPCR. Well... yes and no. 65479 == 0xFFC7 as you point out, however the instruction has 0xFFC3 in it. That's pretty odd. Compiler problem? >>I see you have PBME and LBME enabled (I'm looking at an 8260 manual, >>assuming the 8247 is the same - feel free to correct me :-). Do you >>have a 60x bus and a local bus? Is it possible you are having an >>inadvertant bus error? This wouldn't explain why it only happens when >>you enable the WDT, however. Puzzling. > > > The 8247 does not have local bus, only 60x, but setting/clearing LBME > does not affect the operation. If I don't enable the watchdog the > system works fine. > > Another thing I've noticed, most or even all 8260 based systems have > #undef CONFIG_WATCHDOG > in their config Well, they are a real pain, generally more than they are worth. My co-worker says we had it working on our 8260 board at one point, but Things Changed and it stopped working (it was a never-ending battle to sprinkle enough kick-the-dogs in the start up code) and so it ended up turned off. He said it worked fine once we got through initialization and the was kernel running... gvb