Re: [PATCH 9/9] tcm_qla2xxx: Add special case for COMPARE_AND_WRITEdata_direction

[Nicholas A. Bellinger]

On Tue, 2013-08-20 at 23:37 -0700, Christoph Hellwig wrote:
> On Tue, Aug 20, 2013 at 08:08:00PM +0000, Nicholas A. Bellinger wrote:
> > From: Nicholas Bellinger <nab@xxxxxxxxxxxxx>
> > 
> > Add a special case for COMPARE_AND_WRITE for the reverse data direction
> > mapping used for pci_map_sg() + friends.
> 
> A low level driver is an even worse place to hardcode a specific cdb
> opcode.  As written before this should be done by a flag on the command.
> 

Which means adding another COMPARE_AND_WRITE specific flag to
se_cmd_flags_Table, as the SCF_COMPARE_AND_WRITE_POST is ony set after
the comparsion of the verify instance data is complete..

Is it really worth having two se_cmd_flags for COMPARE_AND_WRITE..?

> Also it might make sense to lift this helper to get a dma direction from
> a command into common code.
> 

Mmm, perhaps.  I don't recall of the top of my head why tcm_qla2xxx
actually needed to reverse it's dma direction (I'm sure that Roland
knows, CC'ed), but IIRC it was a tcm_qla2xxx specific thing..?

--nab

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