[PATCH 1/2] esp_scsi: Correct ordering of PCSCSI definition in esp_rev enum

[Kars de Jong <jongk@linux-m68k.org>]

The order of the definitions in the esp_rev enum is important. The values
are used in comparisons for chip features.

Add a comment to the enum explaining this.

Also, the actual values for the enum fields are irrelevant, so remove the
explicit values (suggested by Geert Uytterhoeven). This makes adding a new
field in the middle of the enum easier.

Finally, move the PCSCSI definition to the right place in the enum. In its
previous location, at the end of the enum, the wrong values are written to
the CONFIG3 register when used with FAST-SCSI targets. Add comments to the
enum explaining this.

Signed-off-by: Kars de Jong <jongk@linux-m68k.org>
---
 drivers/scsi/esp_scsi.c |  2 +-
 drivers/scsi/esp_scsi.h | 19 +++++++++++--------
 2 files changed, 12 insertions(+), 9 deletions(-)

diff --git a/drivers/scsi/esp_scsi.c b/drivers/scsi/esp_scsi.c
index bb88995a12c7..4fc3eee3138b 100644
--- a/drivers/scsi/esp_scsi.c
+++ b/drivers/scsi/esp_scsi.c
@@ -2373,10 +2373,10 @@ static const char *esp_chip_names[] = {
 	"ESP100A",
 	"ESP236",
 	"FAS236",
+	"AM53C974",
 	"FAS100A",
 	"FAST",
 	"FASHME",
-	"AM53C974",
 };
 
 static struct scsi_transport_template *esp_transport_template;
diff --git a/drivers/scsi/esp_scsi.h b/drivers/scsi/esp_scsi.h
index 91b32f2a1a1b..b96cbda03d2d 100644
--- a/drivers/scsi/esp_scsi.h
+++ b/drivers/scsi/esp_scsi.h
@@ -257,15 +257,18 @@ struct esp_cmd_priv {
 };
 #define ESP_CMD_PRIV(CMD)	((struct esp_cmd_priv *)(&(CMD)->SCp))
 
+/* NOTE: this enum is ordered based on chip features! */
 enum esp_rev {
-	ESP100     = 0x00,  /* NCR53C90 - very broken */
-	ESP100A    = 0x01,  /* NCR53C90A */
-	ESP236     = 0x02,
-	FAS236     = 0x03,
-	FAS100A    = 0x04,
-	FAST       = 0x05,
-	FASHME     = 0x06,
-	PCSCSI     = 0x07,  /* AM53c974 */
+	ESP100,  /* NCR53C90 - very broken */
+	ESP100A, /* NCR53C90A */
+	ESP236,
+	/* Chips below this line use ESP_CONFIG3_FSCSI to enable FAST SCSI */
+	FAS236,
+	PCSCSI,  /* AM53c974 */
+	/* Chips below this line use ESP_CONFIG3_FAST to enable FAST SCSI */
+	FAS100A,
+	FAST,
+	FASHME,
 };
 
 struct esp_cmd_entry {
-- 
2.17.1