[PATCH 05/19] scsi: hisi_sas: some optimizations of host controller reset

[John Garry]

From: Xiaofei Tan <tanxiaofei@xxxxxxxxxx>

This patch do following optimizations to host controller reset:
1. Unblock scsi requests before rescanning topology, as SCSI
command need be used if new device is found during rescanning
topology.

2. Remove drain_workqueue(hisi_hba->wq) and
drain_workqueue(shost->work_q), as there is no need to ensure
that all PHYs event are done before exiting host reset.

3. Improve message print level of host reset. Host reset is an
important and very few occurrence event. We should know its progress
even when not debugging.

Signed-off-by: Xiaofei Tan <tanxiaofei@xxxxxxxxxx>
Signed-off-by: John Garry <john.garry@xxxxxxxxxx>
---
 drivers/scsi/hisi_sas/hisi_sas_main.c | 11 ++++-------
 1 file changed, 4 insertions(+), 7 deletions(-)

diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
index 326ecb2..64d51a8 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -1061,8 +1061,6 @@ static void hisi_sas_rescan_topology(struct hisi_hba *hisi_hba, u32 old_state,
 			hisi_sas_phy_down(hisi_hba, phy_no, 0);
 
 	}
-
-	drain_workqueue(hisi_hba->shost->work_q);
 }
 
 static int hisi_sas_controller_reset(struct hisi_hba *hisi_hba)
@@ -1079,7 +1077,7 @@ static int hisi_sas_controller_reset(struct hisi_hba *hisi_hba)
 	if (test_and_set_bit(HISI_SAS_RESET_BIT, &hisi_hba->flags))
 		return -1;
 
-	dev_dbg(dev, "controller resetting...\n");
+	dev_info(dev, "controller resetting...\n");
 	old_state = hisi_hba->hw->get_phys_state(hisi_hba);
 
 	scsi_block_requests(shost);
@@ -1088,6 +1086,7 @@ static int hisi_sas_controller_reset(struct hisi_hba *hisi_hba)
 	if (rc) {
 		dev_warn(dev, "controller reset failed (%d)\n", rc);
 		clear_bit(HISI_SAS_REJECT_CMD_BIT, &hisi_hba->flags);
+		scsi_unblock_requests(shost);
 		goto out;
 	}
 	spin_lock_irqsave(&hisi_hba->lock, flags);
@@ -1100,15 +1099,13 @@ static int hisi_sas_controller_reset(struct hisi_hba *hisi_hba)
 	hisi_hba->hw->phys_init(hisi_hba);
 	msleep(1000);
 	hisi_sas_refresh_port_id(hisi_hba);
-	drain_workqueue(hisi_hba->wq);
-	drain_workqueue(shost->work_q);
+	scsi_unblock_requests(shost);
 
 	state = hisi_hba->hw->get_phys_state(hisi_hba);
 	hisi_sas_rescan_topology(hisi_hba, old_state, state);
-	dev_dbg(dev, "controller reset complete\n");
+	dev_info(dev, "controller reset complete\n");
 
 out:
-	scsi_unblock_requests(shost);
 	clear_bit(HISI_SAS_RESET_BIT, &hisi_hba->flags);
 
 	return rc;
-- 
1.9.1