On Thu, Sep 27, 2012 at 12:04:01PM -0700, Gwendal Grignou wrote:
> This set of patches improve ATA transport classes integration with SCSI
> objects.
>
> Before [2.6.x]
>
> Ata and scsi transport class where separated:
> `--0000:09:00.0
> | `--ata1
> | | `--port_port
> | | `--link1
> | | | `--dev1.0
> | | | `--dev1.1
> | `--ata2
> | ...
> | `--host0
> | | `--scsi_host
> | | | `--host0
> | | `--target0:0:0
> | | | `--0:0:0:0
> | | | | `--block
> | | | | | `--sda
> | | | | | | `--sda1
>
> In 3.2, Lin - in commit 9a6d6a2ddabbd32c07f6a38b659e5f3db319fa5a - addressed
> the issue of linking the ata port with the scsi host object by placing the
> scsi_host object under ata port objects.
>
> However to be more consistent with other transport, this patch does the opposite:
>
> For instance, with SAS transport, We have
> `--0000:0b:00.0
> | `--host6
> | | `--phy-6:0
> | | `--phy-6:1
> ...
> | | `--port-6:0
> | | | `--end_device-6:0
> | | | | `--sas_device
> | | | | | `--end_device-6:0
> | | | | `--sas_end_device
> | | | | | `--end_device-6:0
> | | | | `--target6:0:0
> | | | | | `--6:0:0:0
> | | | | | | `--block
> | | | | | | | `--sdb
> ...
> | | `--port-6:1
> | | | `--end_device-6:1
> ...
> phy and port have to be separated, sas_port are created dynamically.
>
> For ata, all objects are created at initialization time, so the layout is:
> `--0000:09:00.0
> | `--host0
> | | `--port1
> | | | `--link1
> | | | | `--dev1.0
> | | | | | `--target0:0:0
> | | | | | | `--0:0:0:0
> | | | | | | | `--block
> | | | | | | | | `--sda
>
> If we have a port multiplier, more links are created.
> `--0000:09:00.0
> ...
> | `--host4
> | | `--port5
> | | | `--link5
> | | | | `--dev5.0
> [device for the port multiplier]
> | | | `--link5.0
> | | | | `--dev5.0.0
> | | | | | `--target4:0:0
> | | | | | | `--4:0:0:0
> | | | | | | | `--block
> | | | | | | | | `--sdc
> [disk in port 0 of the port multiplier]
> ...
> | | | `--link5.2
> | | | | `--dev5.2.0
> | | | | | `--target4:2:0
> | | | | | | `--4:2:0:0
> | | | | | | | `--block
> | | | | | | | | `--sde
> [disk in port 2 of the port multiplier]
>
> In consequence, the path of a scsi device becomes:
> .../0000:00:1f.2/host0/ata1/link1/dev1.0/target0:0:0/0:0:0:0
~~~~
Should be port1 :-)
> dev1.0 indicates the master device [0] in ata port 1.
> ata1 being under host0, we know the reliationships between the scsi_host id and
> ata port id.
>
> or when a port multiplier is present: for instance the device in port 4 of the
> port multiplier:
> .../0000:00:06.0/0000:09:00.0/host5/ata6/link6.4/dev6.4.0/target5:4:0/5:4:0:0
Same here.
Thanks,
Aaron
>
> Gwendal Grignou (3):
> Revert "ata: make ata port as parent device of scsi host"
> scsi: Allow devices to have arbitrary parent
> libata: Change transport topology layout
>
> drivers/ata/libata-core.c | 13 ++++++-------
> drivers/ata/libata-scsi.c | 4 ++--
> drivers/ata/libata-transport.c | 2 +-
> drivers/firewire/sbp2.c | 3 ++-
> drivers/message/i2o/i2o_scsi.c | 4 ++--
> drivers/scsi/scsi_scan.c | 9 +++++----
> include/scsi/scsi_device.h | 2 +-
> 7 files changed, 19 insertions(+), 18 deletions(-)
>
> --
> 1.7.7.3
>
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