scsi: hisi_sas: Prevent parallel controller reset and control phy command

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.

Link: https://lore.kernel.org/r/1639579061-179473-6-git-send-email-john.garry@huawei.com
Signed-off-by: Qi Liu <liuqi115@huawei.com>
Signed-off-by: John Garry <john.garry@huawei.com>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/hisi_sas/hisi_sas_main.c b/drivers/scsi/hisi_sas/hisi_sas_main.c
index 8df1fd6..9779115 100644 (file)
--- 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;
 }