scsi: hisi_sas: Block requests before take debugfs snapshot

driver inclusion
category: bugfix
bugzilla: https://gitee.com/openeuler/kernel/issues/I7BNF8
CVE: NA

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When the FIO is running and the dump is triggered continuously, some SATA
I/Os fail to be returned to the upper layer due to the setting of
HISI_SAS_REJECT_CMD_BIT. The SCSI layer invokes the error processing
thread. However, sas_ata_hard_reset() also fails to be reset due to the
setting of HISI_SAS_REJECT_CMD_BIT. As a result, the device is disabled.
Call scsi_block_requests() and wait command complete before setting
HISI_SAS_REJECT_CMD_BIT to avoid SATA I/O failures.
Signed-off-by: NYihang Li <liyihang9@huawei.com>
Signed-off-by: Nxiabing <xiabing12@h-partners.com>

drivers/scsi/hisi_sas/hisi_sas_v3_hw.c

@@ -3074,21 +3074,24 @@ static const struct hisi_sas_debugfs_reg debugfs_ras_reg = {
 
 static void debugfs_snapshot_prepare_v3_hw(struct hisi_hba *hisi_hba)
 {
-	set_bit(HISI_SAS_REJECT_CMD_BIT, &hisi_hba->flags);
-
-	hisi_sas_write32(hisi_hba, DLVRY_QUEUE_ENABLE, 0);
+	struct Scsi_Host *shost = hisi_hba->shost;
 
+	scsi_block_requests(shost);
 	wait_cmds_complete_timeout_v3_hw(hisi_hba, 100, 5000);
-
+	set_bit(HISI_SAS_REJECT_CMD_BIT, &hisi_hba->flags);
 	hisi_sas_sync_irqs(hisi_hba);
+	hisi_sas_write32(hisi_hba, DLVRY_QUEUE_ENABLE, 0);
 }
 
 static void debugfs_snapshot_restore_v3_hw(struct hisi_hba *hisi_hba)
 {
+	struct Scsi_Host *shost = hisi_hba->shost;
+
 	hisi_sas_write32(hisi_hba, DLVRY_QUEUE_ENABLE,
 			 (u32)((1ULL << hisi_hba->queue_count) - 1));
 
 	clear_bit(HISI_SAS_REJECT_CMD_BIT, &hisi_hba->flags);
+	scsi_unblock_requests(shost);
 }
 
 static void read_iost_itct_cache_v3_hw(struct hisi_hba *hisi_hba,