libata, libsas: kill pm_result and related cleanup

Tejun says:
  "At least for libata, worrying about suspend/resume failures don't make
   whole lot of sense.  If suspend failed, just proceed with suspend.  If
   the device can't be woken up afterwards, that's that.  There isn't
   anything we could have done differently anyway.  The same for resume, if
   spinup fails, the device is dud and the following commands will invoke
   EH actions and will eventually fail.  Again, there really isn't any
   *choice* to make.  Just making sure the errors are handled gracefully
   (ie. don't crash) and the following commands are handled correctly
   should be enough."

The only libata user that actually cares about the result from a suspend
operation is libsas.  However, it only cares about whether queuing a new
operation collides with an in-flight one.  All libsas does with the
error is retry, but we can just let libata wait for the previous
operation before continuing.

Other cleanups include:
1/ Unifying all ata port pm operations on an ata_port_pm_ prefix
2/ Marking all ata port pm helper routines as returning void, only
   ata_port_pm_ entry points need to fake a 0 return value.
3/ Killing ata_port_{suspend|resume}_common() in favor of calling
   ata_port_request_pm() directly
4/ Killing the wrappers that just do a to_ata_port() conversion
5/ Clearly marking the entry points that do async operations with an
  _async suffix.

Reference: http://marc.info/?l=linux-scsi&m=138995409532286&w=2

Cc: Phillip Susi <psusi@ubuntu.com>
Cc: Alan Stern <stern@rowland.harvard.edu>
Suggested-by: Tejun Heo <tj@kernel.org>
Signed-off-by: Todd Brandt <todd.e.brandt@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>
Signed-off-by: Tejun Heo <tj@kernel.org>

1 files changed, 5 insertions, 30 deletions

diff --git a/drivers/scsi/libsas/sas_ata.c b/drivers/scsi/libsas/sas_ata.c
index d2895836f9fa..766098af4eb7 100644
--- a/drivers/scsi/libsas/sas_ata.c
+++ b/drivers/scsi/libsas/sas_ata.c
@@ -700,46 +700,26 @@ void sas_probe_sata(struct asd_sas_port *port)
 
 }
 
-static bool sas_ata_flush_pm_eh(struct asd_sas_port *port, const char *func)
+static void sas_ata_flush_pm_eh(struct asd_sas_port *port, const char *func)
 {
         struct domain_device *dev, *n;
-        bool retry = false;
 
         list_for_each_entry_safe(dev, n, &port->dev_list, dev_list_node) {
-                int rc;
-
                 if (!dev_is_sata(dev))
                         continue;
 
                 sas_ata_wait_eh(dev);
-                rc = dev->sata_dev.pm_result;
-                if (rc == -EAGAIN)
-                        retry = true;
-                else if (rc) {
-                        /* since we don't have a
-                         * ->port_{suspend|resume} routine in our
-                         *  ata_port ops, and no entanglements with
-                         *  acpi, suspend should just be mechanical trip
-                         *  through eh, catch cases where these
-                         *  assumptions are invalidated
-                         */
-                        WARN_ONCE(1, "failed %s %s error: %d\n", func,
-                                 dev_name(&dev->rphy->dev), rc);
-                }
 
                 /* if libata failed to power manage the device, tear it down */
                 if (ata_dev_disabled(sas_to_ata_dev(dev)))
                         sas_fail_probe(dev, func, -ENODEV);
         }
-
-        return retry;
 }
 
 void sas_suspend_sata(struct asd_sas_port *port)
 {
         struct domain_device *dev;
 
- retry:
         mutex_lock(&port->ha->disco_mutex);
         list_for_each_entry(dev, &port->dev_list, dev_list_node) {
                 struct sata_device *sata;
@@ -751,20 +731,17 @@ void sas_suspend_sata(struct asd_sas_port *port)
                 if (sata->ap->pm_mesg.event == PM_EVENT_SUSPEND)
                         continue;
 
-                sata->pm_result = -EIO;
-                ata_sas_port_async_suspend(sata->ap, &sata->pm_result);
+                ata_sas_port_suspend(sata->ap);
         }
         mutex_unlock(&port->ha->disco_mutex);
 
-        if (sas_ata_flush_pm_eh(port, __func__))
-                goto retry;
+        sas_ata_flush_pm_eh(port, __func__);
 }
 
 void sas_resume_sata(struct asd_sas_port *port)
 {
         struct domain_device *dev;
 
- retry:
         mutex_lock(&port->ha->disco_mutex);
         list_for_each_entry(dev, &port->dev_list, dev_list_node) {
                 struct sata_device *sata;
@@ -776,13 +753,11 @@ void sas_resume_sata(struct asd_sas_port *port)
                 if (sata->ap->pm_mesg.event == PM_EVENT_ON)
                         continue;
 
-                sata->pm_result = -EIO;
-                ata_sas_port_async_resume(sata->ap, &sata->pm_result);
+                ata_sas_port_resume(sata->ap);
         }
         mutex_unlock(&port->ha->disco_mutex);
 
-        if (sas_ata_flush_pm_eh(port, __func__))
-                goto retry;
+        sas_ata_flush_pm_eh(port, __func__);
 }
 
 /**