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Subject: Re: [PATCH 1/2] Avoid bio_endio recursion
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> SCSI. Even the NCQ commands are done via IDE registers, not SCSI command 
> block. It seems like someone wanted to save few weeks of coding by reusing 

Thats really a trivial question of encoding, in all but actual
byte encoding it is SCSI. Once you look at SAS and ATAPI it's all the
more clear.

> the SCSI disk queuing ... and created a lot of other problems (example: if 
> you have disk error with IDE driver, it dumps IDE registers into log ... 
> if you have disk error with SATA driver, it dumps sense key ... but 

Actually it dumps both - and that behaviour was chosen to match existing
drivers in a large part (eg 3ware).