[PATCH 12/21] ufs: Improve static type checking for the host controller state

[Bart Van Assche <bvanassche@acm.org>]

Assign a name to the enumeration type for UFS host controller states and
remove the default clause from switch statements on this enumeration type
to make the compiler warn about unhandled enumeration labels.

Reviewed-by: Avri Altman <avri.altman@wdc.com>
Cc: Can Guo <cang@codeaurora.org>
Signed-off-by: Bart Van Assche <bvanassche@acm.org>
---
 drivers/scsi/ufs/ufshcd.c | 15 ---------------
 drivers/scsi/ufs/ufshcd.h | 25 +++++++++++++++++++++++--
 2 files changed, 23 insertions(+), 17 deletions(-)

diff --git a/drivers/scsi/ufs/ufshcd.c b/drivers/scsi/ufs/ufshcd.c
index 1262f1a63e0b..7091798e6245 100644
--- a/drivers/scsi/ufs/ufshcd.c
+++ b/drivers/scsi/ufs/ufshcd.c
@@ -128,15 +128,6 @@ enum {
 	UFSHCD_CAN_QUEUE	= 32,
 };
 
-/* UFSHCD states */
-enum {
-	UFSHCD_STATE_RESET,
-	UFSHCD_STATE_ERROR,
-	UFSHCD_STATE_OPERATIONAL,
-	UFSHCD_STATE_EH_SCHEDULED_FATAL,
-	UFSHCD_STATE_EH_SCHEDULED_NON_FATAL,
-};
-
 /* UFSHCD error handling flags */
 enum {
 	UFSHCD_EH_IN_PROGRESS = (1 << 0),
@@ -2735,12 +2726,6 @@ static int ufshcd_queuecommand(struct Scsi_Host *host, struct scsi_cmnd *cmd)
 		set_host_byte(cmd, DID_ERROR);
 		cmd->scsi_done(cmd);
 		goto out;
-	default:
-		dev_WARN_ONCE(hba->dev, 1, "%s: invalid state %d\n",
-				__func__, hba->ufshcd_state);
-		set_host_byte(cmd, DID_BAD_TARGET);
-		cmd->scsi_done(cmd);
-		goto out;
 	}
 
 	hba->req_abort_count = 0;
diff --git a/drivers/scsi/ufs/ufshcd.h b/drivers/scsi/ufs/ufshcd.h
index 0dfb5e97ec0d..f8766e8f3cac 100644
--- a/drivers/scsi/ufs/ufshcd.h
+++ b/drivers/scsi/ufs/ufshcd.h
@@ -476,6 +476,27 @@ struct ufs_stats {
 	struct ufs_event_hist event[UFS_EVT_CNT];
 };
 
+/**
+ * enum ufshcd_state - UFS host controller state
+ * @UFSHCD_STATE_RESET: Link is not operational. Postpone SCSI command
+ *	processing.
+ * @UFSHCD_STATE_OPERATIONAL: The host controller is operational and can process
+ *	SCSI commands.
+ * @UFSHCD_STATE_EH_SCHEDULED_NON_FATAL: The error handler has been scheduled.
+ *	SCSI commands may be submitted to the controller.
+ * @UFSHCD_STATE_EH_SCHEDULED_FATAL: The error handler has been scheduled. Fail
+ *	newly submitted SCSI commands with error code DID_BAD_TARGET.
+ * @UFSHCD_STATE_ERROR: An unrecoverable error occurred, e.g. link recovery
+ *	failed. Fail all SCSI commands with error code DID_ERROR.
+ */
+enum ufshcd_state {
+	UFSHCD_STATE_RESET,
+	UFSHCD_STATE_OPERATIONAL,
+	UFSHCD_STATE_EH_SCHEDULED_NON_FATAL,
+	UFSHCD_STATE_EH_SCHEDULED_FATAL,
+	UFSHCD_STATE_ERROR,
+};
+
 enum ufshcd_quirks {
 	/* Interrupt aggregation support is broken */
 	UFSHCD_QUIRK_BROKEN_INTR_AGGR			= 1 << 0,
@@ -687,7 +708,7 @@ struct ufs_hba_monitor {
  * @tmf_tag_set: TMF tag set.
  * @tmf_queue: Used to allocate TMF tags.
  * @pwr_done: completion for power mode change
- * @ufshcd_state: UFSHCD states
+ * @ufshcd_state: UFSHCD state
  * @eh_flags: Error handling flags
  * @intr_mask: Interrupt Mask Bits
  * @ee_ctrl_mask: Exception event control mask
@@ -785,7 +806,7 @@ struct ufs_hba {
 	struct mutex uic_cmd_mutex;
 	struct completion *uic_async_done;
 
-	u32 ufshcd_state;
+	enum ufshcd_state ufshcd_state;
 	u32 eh_flags;
 	u32 intr_mask;
 	u16 ee_ctrl_mask; /* Exception event mask */