Re: [PATCH 1/2 #upstream-fixes] sata_via: fix support for 5287

[Jeff Garzik <jeff@garzik.org>]

Tejun Heo wrote:
> 5287 used to be treated as vt6420 but it didn't work.  It's new family
> of controllers called vt8251 which hosts four SATA ports as M/S of the
> two ATA ports.  This configuration is rather peculiar in that although
> the M/S devices are on the same port, each have its own SCR (or
> equivalent link status/control) registers which screws up the
> port-link-device hierarchy assumed by libata.  Another controller
> which falls into this category is ata_piix w/ SIDPR access.
> 
> libata now has facility to deal with this class of controllers named
> slave_link.  A low level driver for such controllers can just call
> ata_slave_link_init() on the respective ports and libata will handle
> all the difficult parts like following up with single SRST after
> hardresetting both ports.
> 
> This patch creates new controller class vt8251, implements slave_link
> aware init sequence and config space based SCR access for it and moves
> 5287 to the new class.
> 
> This patch is based on Joseph Chan's larger patch which was created
> before slave_link was implemented in libata.
> 
>   http://thread.gmane.org/gmane.linux.kernel.commits.mm/40640
> 
> Signed-off-by: Tejun Heo <tj@kernel.org>
> Cc: Joseph Chan <JosephChan@via.com.tw>
> ---
>  drivers/ata/sata_via.c |  155 +++++++++++++++++++++++++++++++++++++++++++++----
>  1 file changed, 143 insertions(+), 12 deletions(-)

applied