scsi: hisi_sas: Add DFX Feature: Ensure snapshot to be called only one time

Ensure snapshot register action can only be executed for one time
after enable
Signed-off-by: NLuo Jiaxing <luojiaxing@huawei.com>
Signed-off-by: NJohn Garry <john.garry@huawei.com>

Feature or Bugfix: Bugfix
Signed-off-by: Nluojiaxing <luojiaxing@huawei.com>
Reviewed-by: Nhuangdaode <huangdaode@hisilicon.com>

drivers/scsi/hisi_sas/hisi_sas.h

@@ -369,6 +369,7 @@ struct hisi_hba {
 	struct hisi_sas_itct *itct_debugfs;
 
 	struct dentry *debugfs_dir;
+	struct dentry *dump_dentry;
 };
 
 /* Generic HW DMA host memory structures */

drivers/scsi/hisi_sas/hisi_sas_main.c

@@ -1517,8 +1517,9 @@ static int hisi_sas_controller_reset(struct hisi_hba *hisi_hba)
 	struct device *dev = hisi_hba->dev;
 	struct Scsi_Host *shost = hisi_hba->shost;
 	int rc;
-
-	if (hisi_sas_debugfs_enable && hisi_hba->itct_debugfs)
+	if (hisi_sas_debugfs_enable &&
+	    hisi_hba->itct_debugfs &&
+	    !hisi_hba->dump_dentry)
 		queue_work(hisi_hba->wq, &hisi_hba->dfx_work);
 
 	if (!hisi_hba->hw->soft_reset)
@@ -3018,6 +3019,7 @@ static void hisi_sas_create_folder_structure(struct hisi_hba *hisi_hba)
 					&hisi_sas_debugfs_itct_fops))
 		goto fail;
 
+	hisi_hba->dump_dentry = dump_dentry;
 	return;
 fail:
 	debugfs_remove_recursive(hisi_hba->debugfs_dir);