isci: cleanup "starting" state handling

The lldd actively disallows requests in the "starting" state.  Retrying
or holding off commands in this state is sub-optimal:
1/ it adds another state check to the fast path
2/ retrying can cause libsas to give up

However, isci's ->lldd_dev_found() routine already waits for controller
start to complete before allowing further progress.  Checking the
"starting" state in isci_task_execute_task and the isr is redundant and
misleading.  Clean this up and introduce a controller-wide event queue
to start reeling in "completion" proliferation in the driver.

The "stopping" state cleanups are in a similar vein, rely on the the isr
and other paths being precluded from occurring rather than implementing
state checking logic.

Reported-by: Christoph Hellwig <hch@infradead.org>
Cc: Jeff Garzik <jeff@garzik.org>
Signed-off-by: Edmund Nadolski <edmund.nadolski@intel.com>
Signed-off-by: Dan Williams <dan.j.williams@intel.com>

1 files changed, 2 insertions, 2 deletions

diff --git a/drivers/scsi/isci/remote_device.c b/drivers/scsi/isci/remote_device.c
index dbf3c82f619..936f22957e5 100644
--- a/drivers/scsi/isci/remote_device.c
+++ b/drivers/scsi/isci/remote_device.c
@@ -507,6 +507,8 @@ int isci_remote_device_found(struct domain_device *domain_dev)
         dev_dbg(&isci_host->pdev->dev,
                 "%s: domain_device = %p\n", __func__, domain_dev);
 
+        wait_for_start(isci_host);
+
         sas_port = domain_dev->port;
         sas_phy = list_first_entry(&sas_port->phy_list, struct asd_sas_phy,
                                    port_phy_el);
@@ -560,8 +562,6 @@ int isci_remote_device_found(struct domain_device *domain_dev)
                 return -ENODEV;
         }
 
-        wait_for_completion(&isci_host->start_complete);
-
         return 0;
 }
 /**