isci: replace isci_remote_device completion with event queue

Replace the device completion infrastructure with the controller wide
event queue.  There was a potential for the stop and ready notifications
to corrupt each other, now that cannot happen.

The stop pending flag cannot be used until devices are statically
allocated.  We temporarily need to maintain a completion to handle
waiting for an object that has disappeared, but we can at least stop
scribbling on freed memory.

A future change will also get rid of the "stopping" state as it should
not be exposed to the rest of the driver.

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

1 files changed, 13 insertions, 0 deletions

diff --git a/drivers/scsi/isci/host.h b/drivers/scsi/isci/host.h
index 7c1f0b5cee7d..6a6304c06976 100644
--- a/drivers/scsi/isci/host.h
+++ b/drivers/scsi/isci/host.h
@@ -212,6 +212,19 @@ static inline void wait_for_stop(struct isci_host *ihost)
         wait_event(ihost->eventq, !test_bit(IHOST_STOP_PENDING, &ihost->flags));
 }
 
+static inline void wait_for_device_start(struct isci_host *ihost, struct isci_remote_device *idev)
+{
+        wait_event(ihost->eventq, !test_bit(IDEV_START_PENDING, &idev->flags));
+}
+
+static inline void wait_for_device_stop(struct isci_host *ihost, struct isci_remote_device *idev)
+{
+        /* todo switch to:
+         * wait_event(ihost->eventq, !test_bit(IDEV_STOP_PENDING, &idev->flags));
+         * once devices are statically allocated
+         */
+        wait_for_completion(idev->cmp);
+}
 
 /**
  * isci_host_from_sas_ha() - This accessor retrieves the isci_host object