Date: Sun, 21 Jan 2007 18:17:01 -0600
From: Robert Hancock <hancockr@shaw.ca>
Subject: Re: SATA exceptions with 2.6.20-rc5
In-reply-to: <20070121222714.GA2473@atjola.homenet>
To: =?ISO-8859-1?Q?Bj=F6rn_Steinbrink?= <B.Steinbrink@gmx.de>
Cc: Jeff Garzik <jeff@garzik.org>, Chr <chunkeey@web.de>,
       Alistair John Strachan <s0348365@sms.ed.ac.uk>,
       linux-kernel@vger.kernel.org, htejun@gmail.com, jens.axboe@oracle.com,
       lwalton@real.com, pomac@vapor.com
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Bj?rn Steinbrink wrote:
> On 2007.01.21 13:58:01 -0600, Robert Hancock wrote:
>> Bj?rn Steinbrink wrote:
>>> All kernels were bad using that approach. So back to square 1. :/
>>>
>>> Bj?rn
>>>
>> OK guys, here's a new patch to try against 2.6.20-rc5:
>>
>> Right now when switching between ADMA mode and legacy mode (i.e. when 
>> going from doing normal DMA reads/writes to doing a FLUSH CACHE) we just 
>> set the ADMA GO register bit appropriately and continue with no delay. 
>> It looks like in some cases the controller doesn't respond to this 
>> immediately, it takes some nanoseconds for the controller's status 
>> registers to reflect the change that was made. It's possible that if we 
>> were trying to issue commands during this time, the controller might not 
>> react properly. This patch adds some code to wait for the status 
>> register to change to the state we asked for before continuing.
> 
> Just got two exceptions with your patch, none of the debug messages were
> issued.
> 
> Bj?rn

Hmm, another miss, apparently.. Has anyone tried removing these lines
from nv_host_intr in 2.6.20-rc5 sata_nv.c and see what that does?

     /* bail out if not our interrupt */
     if (!(irq_stat & NV_INT_DEV))
         return 0;

-- 
Robert Hancock      Saskatoon, SK, Canada
To email, remove "nospam" from hancockr@nospamshaw.ca
Home Page: http://www.roberthancock.com/


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