[SCSI] megaraid_{mm,mbox}: a fix on INQUIRY with EVPD

With this patch, driver will protect data corruption created by
INQUIRY with EVPD request to megaraid controllers.  As specified in
the changelog, megaraid F/W already has fixed the issue and being
under process of release. Meanwhile, driver will protect the system
with this patch.

Signed-Off By: Seokmann Ju <seokmann.ju@lsil.com>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

Documentation/scsi/ChangeLog.megaraid

@@ -59,6 +59,13 @@ Older Version	: 2.20.4.8 (scsi module), 2.20.2.6 (cmm module)
 	> Buffer I/O error on device sda6, logical block 522067228
 	> attempt to access beyond end of device
 
+2.	When INQUIRY with EVPD bit set issued to the MegaRAID controller,
+	system memory gets corrupted.
+	Root Cause: MegaRAID F/W handle the INQUIRY with EVPD bit set
+	incorrectly.
+	Fix: MegaRAID F/W has fixed the problem and being process of release,
+	soon. Meanwhile, driver will filter out the request.
+
 Release Date	: Mon Apr 11 12:27:22 EST 2006 - Seokmann Ju <sju@lsil.com>
 Current Version : 2.20.4.8 (scsi module), 2.20.2.6 (cmm module)
 Older Version	: 2.20.4.7 (scsi module), 2.20.2.6 (cmm module)

drivers/scsi/megaraid/mega_common.h

@@ -40,6 +40,9 @@
 #define HBA_SIGNATURE_64_BIT		0x299
 #define PCI_CONF_AMISIG64		0xa4
 
+#define MEGA_SCSI_INQ_EVPD		1
+#define MEGA_INVALID_FIELD_IN_CDB	0x24
+
 
 /**
  * scb_t - scsi command control block

drivers/scsi/megaraid/megaraid_mbox.c

@@ -1644,6 +1644,14 @@ megaraid_mbox_build_cmd(adapter_t *adapter, struct scsi_cmnd *scp, int *busy)
 				rdev->last_disp |= (1L << SCP2CHANNEL(scp));
 			}
 
+			if (scp->cmnd[1] & MEGA_SCSI_INQ_EVPD) {
+				scp->sense_buffer[0] = 0x70;
+				scp->sense_buffer[2] = ILLEGAL_REQUEST;
+				scp->sense_buffer[12] = MEGA_INVALID_FIELD_IN_CDB;
+				scp->result = CHECK_CONDITION << 1;
+				return NULL;
+			}
+
 			/* Fall through */
 
 		case READ_CAPACITY: