Re: [PATCH] libsas: move ATA bits into a separate module

[Christoph Hellwig <hch@infradead.org>]

On Wed, Sep 13, 2006 at 05:21:54PM -0700, Darrick J. Wong wrote:
> Hi all,
> 
> Per James Bottomley's request, I've moved all the libsas SATA support
> code into a separate module, named sas_ata.  To satisfy his further
> requirement that libsas not require libata (and vice versa), ata_sas
> maintains fixed function pointer tables to various required functions
> within libsas and libata.  Unfortunately, this means that libsas and
> libata both require sas_ata, but sas_ata is smaller than libata.
> Unloads of libata/libsas at inopportune moments are prevented by
> increasing the refcounts on both modules whenever libsas detects a SATA
> device (and decreasing it when the device goes away, of course).  If the
> module is removed from the .config, then all of hooks into libsas/libata
> should go away.
> 
> This is a rough-cut at separating out the ATA code; please let me know
> what I can improve.  At the moment, I can load and talk to SATA disks
> with the module enabled, as well as watch nothing happen if the module
> is not config'd in.

I think this while idea is flawed.  Please separate out the ATA code
so it can be compiled out whelibata isn't built in, but it defintly
shouldn't be a separate module.  We're not doing any complexity like
that in any other subsystem (we used to do for AGP but got rid of it
again because it caused lots of problems).