Re: [PATCH] libata: add host_set->next for legacy two host sets case

[Jeff Garzik <jgarzik@pobox.com>]

Tejun Heo wrote:
> For a legacy ATA controller, libata registers two separate host sets.
> There was no connection between the two hosts making it impossible to
> traverse all ports related to the controller.  This patch adds
> host_set->next which points to the second host_set and implements
> ata_host_set_for_all_ports() which traverses all ports associated with
> the controller.  This fixes the following bugs.
> 
> * On device removal, all ports hanging off the device are properly
>   detached.  Prior to this patch, ports on the first host_set weren't
>   detached casuing oops on driver unloading.
> 
> * On device removal, both host sets are freed
> 
> This will also be used by new power management code to suspend and
> resume all ports of a controller.  host_set/port representation will
> be improved to handle legacy controllers better and this host_set
> linking hack will go away with it.
> 
> Signed-off-by: Tejun Heo <htejun@gmail.com>

NAK.  You don't want to iterate through multiple host sets, _inside_ of 
function ata_host_set_remove().  ata_host_set_remove() is called with a 
single host_set, and is designed to remove only a single host set.

The concept of a host_set list is OK, but I would rather that 
ata_pci_remove_one() be updated to something like

	host_set = get-drvdata(...)

	while (host_set)
		tmp = host_set
		host_set = host_set->next
		ata_host_set_remove(tmp)