Re: [PATCH UPDATED] libata: add support for ATA_16 on ATAPI

[Tejun Heo <htejun@gmail.com>]

Jeff Garzik wrote:
> Tejun Heo wrote:
>> From: Mark Lord <liml@rtr.ca>
>>
>> Add support for issuing ATA_16 passthru commands to ATAPI devices
>> managed by libata.  It requires the previous CDB length fix patch.
>>
>> A boot/module parameter, "atapi_scmd85=1" can be used to globally
>> disable this feature, if ever desired.
>>
>> tj: renamed ata16_passthru module param to atapi_scmd85 to reduce
>>     confusion
>>
>> tj: restructured __ata_scsi_queuecmd() according to Jeff's suggestion.
>>
>> Signed-off-by: Mark Lord <liml@rtr.ca>
>> Signed-off-by: Tejun Heo <htejun@gmail.com>
>> ---
>> Jeff, Mark, are you guys okay with the modified version?
> 
> Close!  Thanks for revising!
> 
> My only comment now is that I dislike atapi_scmd85.  That means nothing
> to me.
> 
> I liked the old name better.  Or maybe use atapi_passthru16.

The problem with ata16_passthru is that it suggests the opposite of what
it does.  The default value 0 allows ATA_16 passthrough command while
setting it to 1 disallows ATA_16 passthrough and passes through SCSI
Command 0x85 which shares command byte with ATA_16.  Maybe it's because
I'm not a native speaker but the last sentence is pretty difficult to
digest.  So, IMHO, atapi_scmd85 is slightly better in that it means
nothing rather than suggesting the opposite.

How about keeping the old name (or use atapi_passthru16) but flipping
the meaning so that it defaults to 1.  It just makes hell lot of sense
that "ata16_passthru=1" means allowing ATA_16 passthrough not the other
way around.

Thanks.

-- 
tejun