Re: [PATCH 2/2] libata: turn off NCQ if queue depth is adjusted to 1

[Ric Wheeler <ric@emc.com>]

Tejun Heo wrote:

> Ric Wheeler wrote:
>
>
>> We have to be careful with the blacklisting - specifically, drive 
>> model is often less critical than the version of the firmware (which 
>> gets updated as people work drives through qualification, etc).
>> Updating drive firmware for end users is pretty rare (and almost all 
>> tools are still DOS based ;-)).
>>
>> Certain drives should default to non-NCQ (based on model), but we 
>> should be able to enable it if the firmware supports it.
>>
>> Most of the newest drives are fine, but we will still need something 
>> like Tejun's fix to be able to turn it off for the odd cases that 
>> show up in certain odd applications, etc.
>
>
> Ric, can you press harddisk vendors hard enough such that those model 
> and revision numbers squeeze out of them?
>
> Thanks.

I will certainly push to get drive vendors to work with us on this. It 
is in everyone's interest to have the drives avoid stressing features 
that are not stable ;-)

Even better, we can usually try to work the bugs out with vendors before 
the drives become public which should help minimize the issues.