On Mon, Oct 03, 2005 at 04:01:23PM -0400, Alan Stern wrote: > On Mon, 3 Oct 2005, Yedidyah Bar-David wrote: > > > > The device that works with everything except 2.6.14-rc3 is the card > > > reader? > > > > Yes. > > It certainly would be worthwhile getting some debugging logs for > comparison on that. 2.6.14-rc2 and 2.6.14-rc3 don't differ by very much.
OK, I'll make some tomorrow. It's too late now for me :-( > > > The pen drive. > > > > > I was unable to download them (error 404). > > > > Sorry, my mistake - it's in > > <http://www.cs.tau.ac.il/~didi/kernA.log> > > <http://www.cs.tau.ac.il/~didi/kernB.log> > > > > I can also report that it works with 2.6.8-rc1 and does not work with > > 2.6.8-rc2. Which means the regression happened between these two. Can > > anyone tell me how to see individual patches between them? Or I came to > > the finest point in my binary search and should start looking at the > > code? > > At this point you probably want to examine the code. Or at least the > portions that changed between -rc1 and -rc2. That's what I intend to do now (tomorrow). > > However I'm not completely convinced you'll find anything. Those "Medium > not present" messages in your log should never occur with a flash device. > They indicate a hardware or firmware problem. > > It might turn out to be something trivial, like your B machine doesn't > provide sufficient voltage or current on the power connection of the USB > bus. Fine, but why does it work with 2.6.8-rc1? Maybe, for example, it is indeed a hardware bug, which didn't manifest itself in 2.6.8-rc1 because there was somewhere a larger delay that let the bad hardware manage to do its job, and rc2 shortened that delay. Wouldn't it make sense to make the delay larger back? As I said in the first message, BTW, I do know for sure that the hardware is bad. But because it always worked for me well, and still does on some versions, I thought the only problem with it is in a specific part of the memory, not in other parts like the firmware. If you are right, and this indeed should never happen with good hardware, then 1. I am much releaved, and might put the machine to production even without solving this, as I do not particularly care about the specific pen - only used it for testing, 2. It's still a question whether we want linux to support bad hardware if possible. > > Also keep in mind that sometimes failures occur at random. You might get > fooled into thinking a particular kernel release is at fault, simply > because by pure chance the previous release ran okay in your test. I do not understand how that can be. I tried several times to plug it in and out in both versions, and it always worked with rc1 and never with rc2. -- Didi ------------------------------------------------------- This SF.Net email is sponsored by: Power Architecture Resource Center: Free content, downloads, discussions, and more. http://solutions.newsforge.com/ibmarch.tmpl _______________________________________________ [email protected] To unsubscribe, use the last form field at: https://lists.sourceforge.net/lists/listinfo/linux-usb-users
