Date: Tue, 19 Jun 2007 17:17:45 +0100
From: Alan Cox <alan@lxorguk.ukuu.org.uk>
To: Mark Lord <lkml@rtr.ca>
Cc: Sergei Shtylyov <sshtylyov@ru.mvista.com>,
       Linas Vepstas <linas@austin.ibm.com>, linux-ide@vger.kernel.org,
       linux-kernel@vger.kernel.org
Subject: Re: [BUG] ide dma_timer_expiry, then hard lockup
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> >    Indeed... but the thing is we don't know what's asserted in this case 
> > -- remember, it's reading the status register that locks everything up...
> 
> Exactly.  And IORDY shouldn't really apply there,
> unless some nitwit standards person wrote it into a spec..

Could it be we need to reset the state machine at this point before we
touch the registers again - that wouldn't be the first controller with
this limit and undocumented.

On the 370 we already 

Linas; For the debug on the libata one turn on ATA_DEBUG and
ATA_VERBOSE_DEBUG in include/linux/libata.h and it should spew
diagnostics before the freeze. I suspect thats a different problem to the
hang you see now but I'd like to debug both.

Alan
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