[PATCH v2 13/15] scsi: hisi_sas: Keep controller active between ISR of phyup and the event being processed

[chenxiang <chenxiang66@xxxxxxxxxxxxx>]

From: Xiang Chen <chenxiang66@xxxxxxxxxxxxx>

It is possible that controller may become suspended between processing a
phyup interrupt and the event being processed by libsas. As such, we can't
ensure the controller is active when processing the phyup event - this may
 cause the phyup event to be lost or other issues.
To avoid any possible issues, add pm_runtime_get_noresume() in phyup
interrupt handler and pm_runtime_put_sync() in the work handler exit to
ensure that we stay always active. Since we only want to call
pm_runtime_get_noresume() for v3 hw, signal this will a new event,
HISI_PHYE_PHY_UP_PM.

Signed-off-by: Xiang Chen <chenxiang66@xxxxxxxxxxxxx>
Acked-by: John Garry <john.garry@xxxxxxxxxx>
---
 drivers/scsi/hisi_sas/hisi_sas.h       |  1 +
 drivers/scsi/hisi_sas/hisi_sas_main.c  | 22 ++++++++++++++++++++--
 drivers/scsi/hisi_sas/hisi_sas_v3_hw.c |  4 +++-
 3 files changed, 24 insertions(+), 3 deletions(-)

diff --git a/drivers/scsi/hisi_sas/hisi_sas.h b/drivers/scsi/hisi_sas/hisi_sas.h
index 07b473de9136..15a58c955516 100644
--- a/drivers/scsi/hisi_sas/hisi_sas.h
+++ b/drivers/scsi/hisi_sas/hisi_sas.h
@@ -158,6 +158,7 @@ enum hisi_sas_bit_err_type {
 enum hisi_sas_phy_event {
 	HISI_PHYE_PHY_UP   = 0U,
 	HISI_PHYE_LINK_RESET,
+	HISI_PHYE_PHY_UP_PM,
 	HISI_PHYES_NUM,
 };
 
diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
index 051092e294f7..f46f679fe825 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -846,10 +846,11 @@ int hisi_sas_scan_finished(struct Scsi_Host *shost, unsigned long time)
 }
 EXPORT_SYMBOL_GPL(hisi_sas_scan_finished);
 
-static void hisi_sas_phyup_work(struct work_struct *work)
+static void hisi_sas_phyup_work_common(struct work_struct *work,
+		enum hisi_sas_phy_event event)
 {
 	struct hisi_sas_phy *phy =
-		container_of(work, typeof(*phy), works[HISI_PHYE_PHY_UP]);
+		container_of(work, typeof(*phy), works[event]);
 	struct hisi_hba *hisi_hba = phy->hisi_hba;
 	struct asd_sas_phy *sas_phy = &phy->sas_phy;
 	int phy_no = sas_phy->id;
@@ -860,6 +861,11 @@ static void hisi_sas_phyup_work(struct work_struct *work)
 	hisi_sas_bytes_dmaed(hisi_hba, phy_no, GFP_KERNEL);
 }
 
+static void hisi_sas_phyup_work(struct work_struct *work)
+{
+	hisi_sas_phyup_work_common(work, HISI_PHYE_PHY_UP);
+}
+
 static void hisi_sas_linkreset_work(struct work_struct *work)
 {
 	struct hisi_sas_phy *phy =
@@ -869,9 +875,21 @@ static void hisi_sas_linkreset_work(struct work_struct *work)
 	hisi_sas_control_phy(sas_phy, PHY_FUNC_LINK_RESET, NULL);
 }
 
+static void hisi_sas_phyup_pm_work(struct work_struct *work)
+{
+	struct hisi_sas_phy *phy =
+		container_of(work, typeof(*phy), works[HISI_PHYE_PHY_UP_PM]);
+	struct hisi_hba *hisi_hba = phy->hisi_hba;
+	struct device *dev = hisi_hba->dev;
+
+	hisi_sas_phyup_work_common(work, HISI_PHYE_PHY_UP_PM);
+	pm_runtime_put_sync(dev);
+}
+
 static const work_func_t hisi_sas_phye_fns[HISI_PHYES_NUM] = {
 	[HISI_PHYE_PHY_UP] = hisi_sas_phyup_work,
 	[HISI_PHYE_LINK_RESET] = hisi_sas_linkreset_work,
+	[HISI_PHYE_PHY_UP_PM] = hisi_sas_phyup_pm_work,
 };
 
 bool hisi_sas_notify_phy_event(struct hisi_sas_phy *phy,
diff --git a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
index 6d7fde38fe02..94eb48c93ab1 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_v3_hw.c
@@ -1561,7 +1561,9 @@ static irqreturn_t phy_up_v3_hw(int phy_no, struct hisi_hba *hisi_hba)
 
 	phy->port_id = port_id;
 
-	hisi_sas_notify_phy_event(phy, HISI_PHYE_PHY_UP);
+	/* Call pm_runtime_put_sync() with pairs in hisi_sas_phyup_pm_work() */
+	pm_runtime_get_noresume(dev);
+	hisi_sas_notify_phy_event(phy, HISI_PHYE_PHY_UP_PM);
 
 	res = IRQ_HANDLED;
 
-- 
2.33.0