Merge patch series "scsi: hisi_sas: Minor fixes and cleanups"

chenxiang <chenxiang66@hisilicon.com> says:

This series contains some fixes and cleanups including:

 - Fix a deadlock issue related to automatic debugfs;

 - Remove redundant checks for automatic debugfs;

 - Check whether debugfs is enabled before removing or releasing it;

 - Remove hisi_hba->timer for v3 hw;

Link: https://lore.kernel.org/r/1705904747-62186-1-git-send-email-chenxiang66@hisilicon.com
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

Author: martinkpetersen

drivers/scsi/hisi_sas/hisi_sas_main.c

@@ -1507,7 +1507,12 @@ void hisi_sas_controller_reset_prepare(struct hisi_hba *hisi_hba)
 	scsi_block_requests(shost);
 	hisi_hba->hw->wait_cmds_complete_timeout(hisi_hba, 100, 5000);
 
-	del_timer_sync(&hisi_hba->timer);
+	/*
+	 * hisi_hba->timer is only used for v1/v2 hw, and check hw->sht
+	 * which is also only used for v1/v2 hw to skip it for v3 hw
+	 */
+	if (hisi_hba->hw->sht)
+		del_timer_sync(&hisi_hba->timer);
 
 	set_bit(HISI_SAS_REJECT_CMD_BIT, &hisi_hba->flags);
 }
@@ -1573,7 +1578,7 @@ static int hisi_sas_controller_prereset(struct hisi_hba *hisi_hba)
 		return -EPERM;
 	}
 
-	if (hisi_sas_debugfs_enable && hisi_hba->debugfs_itct[0].itct)
+	if (hisi_sas_debugfs_enable)
 		hisi_hba->hw->debugfs_snapshot_regs(hisi_hba);
 
 	return 0;
@@ -1961,10 +1966,18 @@ static bool hisi_sas_internal_abort_timeout(struct sas_task *task,
 	struct hisi_hba *hisi_hba = dev_to_hisi_hba(device);
 	struct hisi_sas_internal_abort_data *timeout = data;
 
-	if (hisi_sas_debugfs_enable && hisi_hba->debugfs_itct[0].itct) {
-		down(&hisi_hba->sem);
+	if (hisi_sas_debugfs_enable) {
+		/*
+		 * If timeout occurs in device gone scenario, to avoid
+		 * circular dependency like:
+		 * hisi_sas_dev_gone() -> down() -> ... ->
+		 * hisi_sas_internal_abort_timeout() -> down().
+		 */
+		if (!timeout->rst_ha_timeout)
+			down(&hisi_hba->sem);
 		hisi_hba->hw->debugfs_snapshot_regs(hisi_hba);
-		up(&hisi_hba->sem);
+		if (!timeout->rst_ha_timeout)
+			up(&hisi_hba->sem);
 	}
 
 	if (task->task_state_flags & SAS_TASK_STATE_DONE) {
@@ -2617,7 +2630,8 @@ static __exit void hisi_sas_exit(void)
 {
 	sas_release_transport(hisi_sas_stt);
 
-	debugfs_remove(hisi_sas_debugfs_dir);
+	if (hisi_sas_debugfs_enable)
+		debugfs_remove(hisi_sas_debugfs_dir);
 }
 
 module_init(hisi_sas_init);

drivers/scsi/hisi_sas/hisi_sas_v3_hw.c

@@ -4902,7 +4902,8 @@ hisi_sas_v3_probe(struct pci_dev *pdev, const struct pci_device_id *id)
 err_out_remove_host:
 	scsi_remove_host(shost);
 err_out_undo_debugfs:
-	debugfs_exit_v3_hw(hisi_hba);
+	if (hisi_sas_debugfs_enable)
+		debugfs_exit_v3_hw(hisi_hba);
 err_out_free_host:
 	hisi_sas_free(hisi_hba);
 	scsi_host_put(shost);
@@ -4934,15 +4935,16 @@ static void hisi_sas_v3_remove(struct pci_dev *pdev)
 	struct Scsi_Host *shost = sha->shost;
 
 	pm_runtime_get_noresume(dev);
-	del_timer_sync(&hisi_hba->timer);
 
 	sas_unregister_ha(sha);
 	flush_workqueue(hisi_hba->wq);
 	sas_remove_host(shost);
 
 	hisi_sas_v3_destroy_irqs(pdev, hisi_hba);
 	hisi_sas_free(hisi_hba);
-	debugfs_exit_v3_hw(hisi_hba);
+	if (hisi_sas_debugfs_enable)
+		debugfs_exit_v3_hw(hisi_hba);
+
 	scsi_host_put(shost);
 }