[PATCH 5/7] scsi: hisi_sas: Add device link between SCSI devices and hisi_hba

[John Garry]

From: Xiang Chen <chenxiang66@xxxxxxxxxxxxx>

Runtime PM of SCSI devices are already supported in SCSI layer, we can
suspend/resume every SCSI device separately. But if there is not link
between hisi_hba and SCSI devices or SCSI targets, it will cause issues
if the controller is suspended while SCSI devices are still resuming.
If only when all the SCSI devices under the controller are suspended,
the controller can be suspended. So add the device link between
SCSI devices and the controller.

Signed-off-by: Xiang Chen <chenxiang66@xxxxxxxxxxxxx>
Signed-off-by: John Garry <john.garry@xxxxxxxxxx>
---
 drivers/scsi/hisi_sas/hisi_sas_v3_hw.c | 29 +++++++++++++++++++++++++-
 1 file changed, 28 insertions(+), 1 deletion(-)

diff --git a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
index 708b5661b127..c9353e02fdd5 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
@@ -2758,6 +2758,33 @@ static ssize_t intr_coal_count_v3_hw_store(struct device *dev,
 }
 static DEVICE_ATTR_RW(intr_coal_count_v3_hw);
 
+static int slave_configure_v3_hw(struct scsi_device *sdev)
+{
+	struct Scsi_Host *shost = dev_to_shost(&sdev->sdev_gendev);
+	struct domain_device *ddev = sdev_to_domain_dev(sdev);
+	struct hisi_hba *hisi_hba = shost_priv(shost);
+	struct device *dev = hisi_hba->dev;
+	int ret = sas_slave_configure(sdev);
+
+	if (ret)
+		return ret;
+	if (!dev_is_sata(ddev))
+		sas_change_queue_depth(sdev, 64);
+
+	if (sdev->type == TYPE_ENCLOSURE)
+		return 0;
+
+	if (!device_link_add(&sdev->sdev_gendev, dev,
+			     DL_FLAG_PM_RUNTIME | DL_FLAG_RPM_ACTIVE)) {
+		if (pm_runtime_enabled(dev)) {
+			dev_info(dev, "add device link failed, disable runtime PM for the host\n");
+			pm_runtime_disable(dev);
+		}
+	}
+
+	return 0;
+}
+
 static struct device_attribute *host_attrs_v3_hw[] = {
 	&dev_attr_phy_event_threshold,
 	&dev_attr_intr_conv_v3_hw,
@@ -3114,7 +3141,7 @@ static struct scsi_host_template sht_v3_hw = {
 	.queuecommand		= sas_queuecommand,
 	.dma_need_drain		= ata_scsi_dma_need_drain,
 	.target_alloc		= sas_target_alloc,
-	.slave_configure	= hisi_sas_slave_configure,
+	.slave_configure	= slave_configure_v3_hw,
 	.scan_finished		= hisi_sas_scan_finished,
 	.scan_start		= hisi_sas_scan_start,
 	.change_queue_depth	= sas_change_queue_depth,
-- 
2.26.2