scsi: aha1542: Clarify 'struct ccb' comments

This driver's original authors did pretty bad job of documenting the
Command Control Block (CCB) structure -- especially its 2nd byte, where the
bit numbers were completely left out. Sync up the 'struct ccb' comments to
the Adaptec AHA-154xA manual.

Link: https://lore.kernel.org/r/17a7be14-a9d2-9822-bb3e-1d7385f486b0@omprussia.ru
Reviewed-by: Hannes Reinecke <hare@suse.de>
Signed-off-by: Sergey Shtylyov <s.shtylyov@omprussia.ru>
Signed-off-by: Martin K. Petersen <martin.petersen@oracle.com>

diff --git a/drivers/scsi/aha1542.h b/drivers/scsi/aha1542.h
index f5b0d21..92a5f98 100644 (file)
--- a/drivers/scsi/aha1542.h
+++ b/drivers/scsi/aha1542.h
@@ -78,23 +78,28 @@ static inline void any2scsi(u8 *p, u32 v)
 #define MAX_CDB 12
 #define MAX_SENSE 14
 
-struct ccb {           /* Command Control Block 5.3 */
-       u8 op;          /* Command Control Block Operation Code */
-       u8 idlun;       /* op=0,2:Target Id, op=1:Initiator Id */
-                       /* Outbound data transfer, length is checked*/
-                       /* Inbound data transfer, length is checked */
-                       /* Logical Unit Number */
+/* Command Control Block (CCB), 5.3 */
+struct ccb {
+       u8 op;          /* Command Control Block Operation Code: */
+                       /* 0x00: SCSI Initiator CCB, 0x01: SCSI Target CCB, */
+                       /* 0x02: SCSI Initiator CCB with Scatter/Gather, */
+                       /* 0x81: SCSI Bus Device Reset CCB */
+       u8 idlun;       /* Address and Direction Control: */
+                       /* Bits 7-5: op=0, 2: Target ID, op=1: Initiator ID */
+                       /* Bit  4: Outbound data transfer, length is checked */
+                       /* Bit  3:  Inbound data transfer, length is checked */
+                       /* Bits 2-0: Logical Unit Number */
        u8 cdblen;      /* SCSI Command Length */
-       u8 rsalen;      /* Request Sense Allocation Length/Disable */
-       u8 datalen[3];  /* Data Length (msb, .., lsb) */
-       u8 dataptr[3];  /* Data Pointer */
-       u8 linkptr[3];  /* Link Pointer */
+       u8 rsalen;      /* Request Sense Allocation Length/Disable Auto Sense */
+       u8 datalen[3];  /* Data Length  (MSB, ..., LSB) */
+       u8 dataptr[3];  /* Data Pointer (MSB, ..., LSB) */
+       u8 linkptr[3];  /* Link Pointer (MSB, ..., LSB) */
        u8 commlinkid;  /* Command Linking Identifier */
-       u8 hastat;      /* Host Adapter Status (HASTAT) */
-       u8 tarstat;     /* Target Device Status */
+       u8 hastat;      /* Host  Adapter Status (HASTAT) */
+       u8 tarstat;     /* Target Device Status (TARSTAT) */
        u8 reserved[2];
-       u8 cdb[MAX_CDB+MAX_SENSE];      /* SCSI Command Descriptor Block */
-                                       /* REQUEST SENSE */
+       u8 cdb[MAX_CDB + MAX_SENSE];    /* SCSI Command Descriptor Block */
+                                       /* followed by the Auto Sense data */
 };
 
 #define AHA1542_REGION_SIZE 4