Re: [PATCH 1/6] libata: separate out ata_dev_read_id()

[Jeff Garzik <jgarzik@pobox.com>]

Tejun Heo wrote:
> Separate out ata_dev_read_id() from ata_dev_identify().  This is the
> first half of splitting ata_dev_identify().  ata_dev_read_id() will
> also be used for revalidation.  This patch does not make any behavior
> change.
> 
> ata_dev_read_id() doesn't modify any of libata-internal data
> structures.  It simply reads IDENTIFY page and returns error code on
> failure.  INIT_DEV_PARAMS and EDD wrong class code are also handled by
> this function.
> 
> Re-reading IDENTIFY after INIT_DEV_PARAMS is performed by jumping to
> retry: instead of calling ata_dev_reread_id().  This is done because
> 1. there's retry label anyway 2. ata_dev_reread_id() cannot be used
> anywhere else so there's no reason to keep it.
> 
> This function is probably the place to set transfer mode to PIO0
> before IDENTIFY.  However, reset -> identify -> init_dev_params order
> should be kept for pre-ATA4 devices so we cannot set transfer mode
> before IDENTIFY for them.  How do we know if a device is post-ATA4
> before IDENTIFY?
> 
> Signed-off-by: Tejun Heo <htejun@gmail.com>

applied 1-2, will get to the rest a bit later, after other work and some 
testing of this work.

	Jeff