[PATCH 5/8] scsi: hisi_sas: Prevent parallel controller reset and control phy command

[John Garry <john.garry@huawei.com>]

From: Qi Liu <liuqi115@huawei.com>

A user may issue a control phy command from sysfs at any time, even if the
controller is resetting.

If a phy is disabled by hardreset/linkreset command before calling
get_phys_state() in the reset path, the saved phy state may be incorrect.

To avoid incorrectly recording the phy state, use hisi_hba.sem to ensure
that the controller reset may not run at the same time as when the phy
control function is running.

Signed-off-by: Qi Liu <liuqi115@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
---
 drivers/scsi/hisi_sas/hisi_sas_main.c | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
index 8df1fd680eac..977911580d8f 100644
--- a/drivers/scsi/hisi_sas/hisi_sas_main.c
+++ b/drivers/scsi/hisi_sas/hisi_sas_main.c
@@ -1148,6 +1148,7 @@ static int hisi_sas_control_phy(struct asd_sas_phy *sas_phy, enum phy_func func,
 	u8 sts = phy->phy_attached;
 	int ret = 0;
 
+	down(&hisi_hba->sem);
 	phy->reset_completion = &completion;
 
 	switch (func) {
@@ -1191,6 +1192,7 @@ static int hisi_sas_control_phy(struct asd_sas_phy *sas_phy, enum phy_func func,
 out:
 	phy->reset_completion = NULL;
 
+	up(&hisi_hba->sem);
 	return ret;
 }
 
-- 
2.26.2