2012/3/16 Jack Wang [off-list ref]:

Dan,

I found problem about SATA error handle and this also led to panic when run suspend/resume test. Thanks again for your share debug method and patch of testing suspend/resume problem.

The problem is:

When probe libata probe sata will try to reset device and send IDENTIFY DEVICE.. commands when 3 times fail will give up but never tell libsas and lldd to clean up the resource. And if some time later the device came up report BROADCAST CHANGE and libsas found device try to  tell lldd, but lldd is not forget the original one will reject this.
Should we export sas_unregister_devs_sas_addr let ata call this when give up.

Have a look at "libsas: fix ata_eh clobbering ex_phys via
smp_ata_check_ready" [1], this fixed up cases where libsas failed to
handle ata device unplug in our environment.

--
Dan

[1]: http://marc.info/?l=linux-scsi&m=133239709603452&w=2