Messages in this thread | | | From | "Michael S. Zick" <> | Subject | Re: Null Pointer BUG in uhci_hcd | Date | Wed, 8 Jul 2009 17:31:29 -0500 |
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On Wed July 8 2009, Alan Stern wrote: > On Wed, 8 Jul 2009, Michael S. Zick wrote: > > > > Like I've been telling you all along, the hardware isn't working. > > > > > > > That sounds very fragile. > > I'm not sure how to interpret that sentence. If you mean that your > system's hardware design isn't good, I agree. If you mean that the > kernel shouldn't produce a lot of output when faced with broken > hardware, that's not so clear. What else should it do (bearing in mind > that the kernel can't tell the hardware is broken)? >
It is unlikely that VIA Tech. will recall the CX700 chipset.
So being able to take a device off-line (like the driver claims it is doing) and *leave* it off-line - until told to "try again" - that would be an improvement.
The current process of filling up the /var/log directory until the machine chokes is a rather fragile sort of response to a hot-plugged device, good or bad.
> > > I suspect it's worse than a simple interrupt-routing mistake. > > > > > > > I would not object to your removing that one mistake - that is one less > > to contend with. > > I didn't say there was an interrupt-routing mistake; I said it was > _worse_ than an interrupt-routing mistake. >
Never claimed you did - the driver made that claim. But still, it would be nice to get rid of the interrupt-routing mistake.
I suppose waiting for the OLPC project to find and fix the problem is a viable alternative also. You will not be the first to give up on this C7-M/CX700 combination. ;)
> > > > > > For more information enable CONFIG_USB_DEBUG and CONFIG_DEBUG_FS, then > > > > > > see what's sitting in the usb/uhci/* files in debugfs. > > > > > > > > > > > > > > Fours up-time - nothing written to dmesg since boot - > > Just the usual hard-lockup. > > > > Also - something in the combined fix/diagnostic patch > > disable any sensing of external usb events. > > So I couldn't very well poke devices at it. ;) > > You should take out those BUG statements. If they ever trigger, they > will certainly lock up your system. >
Although I would expect that they not do so silently.
I take them out and just in time before starting the next round of testing.
Mike > Alan Stern > > >
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