[SCSI] libsas: poll for ata device readiness after reset

Use ata_wait_after_reset() to poll for link recovery after a reset.
This combined with sas_ha->eh_mutex prevents expander rediscovery from
probing phys in an intermediate state.  Local discovery does not have a
mechanism to filter link status changes during this timeout, so it
remains the responsibility of lldds to prevent premature port teardown.
Although once all lldd's support ->lldd_ata_check_ready() that could be
used as a gate to local port teardown.

The signature fis is re-transmitted when the link comes back so we
should be revalidating the ata device class, but that is left to a future
patch.

Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: James Bottomley <JBottomley@Parallels.com>

1 files changed, 1 insertions, 0 deletions

diff --git a/include/scsi/libsas.h b/include/scsi/libsas.h
index 18704a2e4f07..2079b18467a1 100644
--- a/include/scsi/libsas.h
+++ b/include/scsi/libsas.h
@@ -615,6 +615,7 @@ struct sas_domain_function_template {
         int (*lldd_clear_task_set)(struct domain_device *, u8 *lun);
         int (*lldd_I_T_nexus_reset)(struct domain_device *);
         int (*lldd_ata_soft_reset)(struct domain_device *);
+        int (*lldd_ata_check_ready)(struct domain_device *);
         void (*lldd_ata_set_dmamode)(struct domain_device *);
         int (*lldd_lu_reset)(struct domain_device *, u8 *lun);
         int (*lldd_query_task)(struct sas_task *);