[SCSI] libsas: don't recover end devices attached to disabled phys

If userspace has decided to disable a phy the kernel should honor that
and not inadvertantly re-enable the phy via error recovery.  This is
more straightforward in the sata case where link recovery (via
libata-eh) is separate from sas_task cancelling in libsas-eh.  Teach
libsas to accept -ENODEV as a successful response from I_T_nexus_reset
('successful' in terms of not escalating further).

This is a more comprehensive fix then "libsas: don't recover 'gone'
devices in sas_ata_hard_reset()", as it is no longer sata-specific.

aic94xx does check the return value from sas_phy_reset() so if the phy
is disabled we proceed with clearing the I_T_nexus.

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

1 files changed, 2 insertions, 3 deletions

diff --git a/drivers/scsi/libsas/sas_ata.c b/drivers/scsi/libsas/sas_ata.c
index 08d2103a45b7..bc0cecc6ad62 100644
--- a/drivers/scsi/libsas/sas_ata.c
+++ b/drivers/scsi/libsas/sas_ata.c
@@ -407,10 +407,9 @@ static int sas_ata_hard_reset(struct ata_link *link, unsigned int *class,
         struct domain_device *dev = ap->private_data;
         struct sas_internal *i = dev_to_sas_internal(dev);
 
-        if (test_bit(SAS_DEV_GONE, &dev->state))
-                return -ENODEV;
-
         res = i->dft->lldd_I_T_nexus_reset(dev);
+        if (res == -ENODEV)
+                return res;
 
         if (res != TMF_RESP_FUNC_COMPLETE)
                 sas_ata_printk(KERN_DEBUG, dev, "Unable to reset ata device?\n");