sas_device/end_device-*/phy_identifier flipped

[Douglas Gilbert <dougg@torque.net>]

In lk 2.6.20-rc2 (and probably earlier) the phy_identifier
attribute in the /sys/class/sas_device/end_device-*
directory is showing the wrong end of the point to point
link.

Phy identifiers on (dual ported) SAS disks are typically
0 and 1. For SATA disks the phy identifier should be 0.

# lsscsi
[4:0:0:0]    disk    ATA      ST3160812AS      D     /dev/sda
[4:0:1:0]    disk    SEAGATE  ST336754SS       0003  /dev/sdb
# lsscsi -t
[4:0:0:0]    disk    sas:0x500605b0000033e6          /dev/sda
[4:0:1:0]    disk    sas:0x5000c500005208ee          /dev/sdb
# lsscsi -tL 4:0:1:0
[4:0:1:0]    disk    sas:0x5000c500005208ee          /dev/sdb
  transport=sas
  initiator_port_protocols=none
  initiator_response_timeout=10000
  I_T_nexus_loss_timeout=1744
  phy_identifier=7
  ready_led_meaning=1
  sas_address=0x5000c500005208ee
  target_port_protocols=ssp

# smp_discover -mb
Device <500605b0000033ef>, expander (only connected phys shown):
  phy   5:T:attached:[500605b00006f260:03  i(SSP+STP+SMP)]  3 Gbps
  phy   6:T:attached:[500605b0000033e6:00  t(SATA)]  1.5 Gbps
  phy   7:T:attached:[5000c500005208ee:01  t(SSP)]  3 Gbps


The SATA and SAS disks are connected via an expander which
lets me look at sysfs for 4:0:1:0 and the expander configuration
with smp_discover. The port in use on the SAS disk has the
address: 5000c500005208ee . The expander says that cable is
attached to phy 1 which agrees with what I can see. However
sysfs reports "phy_identifier=7" which is wrong (and happens
to be the attached phy_id seen from the SAS disk).

Both aic94xx and mptsas drivers do the same thing so it
looks like a SAS transport problem.

Doug Gilbert