Re: [PATCH 7/9] libata-acpi: improve _GTF execution error handling and reporting

[Mark Lord <liml@rtr.ca>]

Tejun Heo wrote:
> Mark Lord wrote:
>> Tejun Heo wrote:
>>> Mark Lord wrote:
>>>> Tejun Heo wrote:
>>>>> As _GTF commands can't transfer data, device error never signals
>>>>> transfer error.  It indicates that the device vetoed the operation, so
>>>>> it's meaningless to retry.
>>>> ..
>>>>
>>>> The SECURITY commands may pass a data block to the drive,
>>>> containing the password required to unlock/freeze a drive.
>>>> I suspect ACPI on many machines will issue such a command,
>>>> and it does indeed transfer data (512 bytes).
>>> Surprise, ACPI _GTF can't do that.  Don't ask me why.  :-)
>> ..
>>
>> Then why are we (going to be) filtering those op's (one of your patches) ?
> 
> Filtered ones are not LOCK / FREEZE LOCK commands which prevent further
> changes.  e.g. SET MAX FREEZE LOCK will prevent further size changes
> using SET MAX [EXT].  It's bad for three reasons 1. it locks down drive
> feature without user consent (e.g. can't unlock HPA) 2. it makes
> debugging difficult by putting drives into different states 3. it just
> doesn't serve any good.
..

Okay-dokey.  I think I mis-read which FREEZE command was in the patch.

Cheers!