panic: trap: memory address not aligned in ata_prtdev() with Nov 18 GENERIC

[Robert Watson]

On Mon, 1 Dec 2003, Thomas Moestl wrote:

> This can happen when an ATA operation times out, and is caused by an
> access to a freed structure. I have attached a workaround; IIRC sos is
> developing a more complete fix for this. 
> 
> ISTR the timeouts were caused by the fact that Blade 100s come with
> ATA66-capable disks and controllers, but a non-ATA66 (40 pin) cable, and
> that for some reason the driver check to catch this situation did not
> work. I am not seeing this on my machine because I replaced the cable
> long ago when I added another disk. 
> 
> Can you confirm that your box does only have a 40 pin cable? 

Didn't get a chance to open up the box today, however, I did apply the
patch.  It doesn't panic, ... but it does now hang solid.

FreeBSD/sparc64 (ray.rv.nailabs.com) (screen)

login: ad0: WARNING - WRITE_DMA recovered from missing interrupt
ad0: WARNING - READ_DMA recovered from missing interrupt
<hang>

I'll reset the box and rebuild the kernel with BREAK_TO_DEBUGGER, assuming
I can keep it up that long.

Robert N M Watson             FreeBSD Core Team, TrustedBSD Projects
robert at fledge.watson.org      Senior Research Scientist, McAfee Research