Re: [PATCH] libata: remove unlock+relock cycle in ata_scsi_queuecmd

[Christoph Hellwig <hch@infradead.org>]

> Right ... I couldn't persuade anyone else to do it, so I'll probably end
> up coding it.  It looks like the serial number zero check might be
> bogus.  If so I'll remove it, then push the serial number acquisition
> down only into the locked queuecommand of only those drivers that
> actually use it (which were listed in the quoted email, and which might
> have a big impetus to remove it if the use is trivial).  Then we can
> begin unwinding the locking.

In dc395x, eata_pio, in2000, lpfc, megaraid_legacy, megaraid_mbox,
megaraid_sas, mesh, ncr53c8xx, qla1280, qla4xxx, wd33c93 and i2o_scsi
use it in printks only, and all this can be safely removed.

Except for EH that only leaves dpt_i2o, eata, mpt2sas, u14-34f, mptscsi
as non-trivial users.  If you sort out the EH side I'll volunteer to
kill the printks and add private serial numbers to the five drivers
mentioned above.