From mboxrd@z Thu Jan 1 00:00:00 1970 Message-ID: <393DBB5F.DB509DA@charter.net> Date: Tue, 06 Jun 2000 22:02:55 -0500 From: "Dan A. Dickey" MIME-Version: 1.0 To: Murray Jensen CC: Dan Malek , linuxppc-embedded@lists.linuxppc.org Subject: Re: 8xx MMU Table Walk Base (was Re: kernel crashes at InstructionTLBMiss ) References: <23333.960273068@msa.cmst.csiro.au> Content-Type: text/plain; charset=us-ascii Sender: owner-linuxppc-embedded@lists.linuxppc.org List-Id: Murray Jensen wrote: > > On Mon, 05 Jun 2000 16:37:55 -0400, Dan Malek writes: ... > >After reading your diatribe > > Diatribe? Hmm.. Sorry, I didn't mean to offend you - I thought I was being > reasonably clear, and definitely polite. ... > >Finally, lots of bugs associated with porting to new hardware manifest > >themselves as "problems" in any VM related function. Since many people > >don't understand the subtle interactions of all of these functions (as > >evidenced by your message) you become convinced the problem is associated > >with this complexity and fail to unravel the clues to the real cause. > > I don't think I deserve this sort of belittling. Treating potential > contributors in this way can only have a negative effect on open > source development. Murray, please - hang in there. We need more people like you. Cut Dan some slack - he appears to be a genius at programming, but maybe is a little short on people skills. He means no harm, but calls them as he sees them. And as in baseball, not everyone always agrees with the umpire. :) (At least; this is the impression I've gathered in the relatively short time I've made his acquaintance and have been reading this list). > > >some silicon > >bug not understood, > > I included my chip revision above. It appears to be a C1 revision chip. > > >or prototype hardware not working correctly. > > Definitely. > > >There are lots of products and systems in development running this software, > >so you have to approach this generic software from the assumption that > >it is first likely to be working. > > I did. I said I was intrigued as to why this problem only affected me. And > once I make the described change, the "generic software" works for me also > (at least an older revision works - current revisions still crash, something > to do with the memory allocation stuff, I believe). > > As I said in my previous message, I suspect something else I am doing is > triggering this bug (that much is obvious), but there are two possibilities: > either I am doing something wrong in my local changes, or the "generic > software" has a bug which does not show up in anyone else's implementation. I > was wondering whether the latter was the case (I wasn't blaming anyone, I was > excited that maybe I had discovered a long existing hidden fault in the > software, that may explain some mysterious failure modes, that someone else > might be getting - other developers may then post, saying "yeah, that would > explain my problem, blah blah", and so the discussion goes on. Upon searching > the archives, I found that a similar problem had been discussed for the 2.2.x > kernels, so maybe the fix or fixes didn't make their way into the 2.[34].x > kernels. I don't know, anything is possible, that's why we have these > discussion groups). Murray, as far as I know - you are maybe the only one running 2.3.x on a powerpc. Most of the kernels that one can find lying about are 2.2.x (13/14? Can't remember at the moment). I, as well as others, definitely want to see 2.3.x or 2.4.0 running on an embedded powerpc. ... > Again, apologies for not providing enough information in my message - I made > assumptions I shouldn't have. Obviously, on my first post I should have been > completely anal, because no-one knows me from a bar of soap. I can then start > to be less exacting after I have been around for a while. Everyone enjoys sarcasm... :) (Don't they?) > >Where did you get the sources? What > >patches did you apply? What are your hardware details? What > >modifications did you make? > > See above. > > >As for 2.4.xx, the 8xx still doesn't work correctly. However, I > >discovered it failed to work after the 403 additions, so I am now > >learning about the 403 in an effort to make everything live happily > >together again. > > It was my feeling that the problems were to do with the new memory allocation > stuff introduced a couple of months ago. > > >Note, this has nothing to do with M_TWB...... > > I know. Now that we have gotten past treating me like a dill, please can you > re-read my original message and see if I am making any sense at all? I would > very much appreciate some insights and even constructive criticism. Cheers! > Murray... > > PS: I haven't contributed the Cogent platform changes yet, because I wasn't > happy that I had done everything properly. This was really my first foray > into taking part in the Linux/PPC embedded development community - I can't > say it has been particularly successful (despite my good feelings about > contributing a small fix a couple of days ago). I will try not to be too > discouraged. That's the spirit! -Dan (A different one). ** Sent via the linuxppc-embedded mail list. See http://lists.linuxppc.org/