[SCSI] Allow nvram settings to determine bus mode

The PDC code can set the bus mode, but we were ignoring that setting.
Also move the code that determines bus mode into its own function.
Signed-off-by: Matthew Wilcox <matthew@wil.cx>
Signed-off-by: James Bottomley <James.Bottomley@SteelEye.com>

drivers/scsi/sym53c8xx_2/sym_hipd.c

@@ -647,6 +647,37 @@ static void sym_save_initial_setting (struct sym_hcb *np)
 		np->sv_ctest5	= INB(np, nc_ctest5) & 0x24;
 }
 
+/*
+ *  Set SCSI BUS mode.
+ *  - LVD capable chips (895/895A/896/1010) report the current BUS mode
+ *    through the STEST4 IO register.
+ *  - For previous generation chips (825/825A/875), the user has to tell us
+ *    how to check against HVD, since a 100% safe algorithm is not possible.
+ */
+static void sym_set_bus_mode(struct sym_hcb *np, struct sym_nvram *nvram)
+{
+	if (np->scsi_mode)
+		return;
+
+	np->scsi_mode = SMODE_SE;
+	if (np->features & (FE_ULTRA2|FE_ULTRA3))
+		np->scsi_mode = (np->sv_stest4 & SMODE);
+	else if	(np->features & FE_DIFF) {
+		if (SYM_SETUP_SCSI_DIFF == 1) {
+			if (np->sv_scntl3) {
+				if (np->sv_stest2 & 0x20)
+					np->scsi_mode = SMODE_HVD;
+			} else if (nvram->type == SYM_SYMBIOS_NVRAM) {
+				if (!(INB(np, nc_gpreg) & 0x08))
+					np->scsi_mode = SMODE_HVD;
+			}
+		} else if (SYM_SETUP_SCSI_DIFF == 2)
+			np->scsi_mode = SMODE_HVD;
+	}
+	if (np->scsi_mode == SMODE_HVD)
+		np->rv_stest2 |= 0x20;
+}
+
 /*
  *  Prepare io register values used by sym_start_up() 
  *  according to selected and supported features.
@@ -657,10 +688,7 @@ static int sym_prepare_setting(struct Scsi_Host *shost, struct sym_hcb *np, stru
 	u32	period;
 	int i;
 
-	/*
-	 *  Wide ?
-	 */
-	np->maxwide	= (np->features & FE_WIDE)? 1 : 0;
+	np->maxwide = (np->features & FE_WIDE) ? 1 : 0;
 
 	/*
 	 *  Guess the frequency of the chip's clock.
@@ -841,6 +869,7 @@ static int sym_prepare_setting(struct Scsi_Host *shost, struct sym_hcb *np, stru
 	 *  Get parity checking, host ID and verbose mode from NVRAM
 	 */
 	np->myaddr = 255;
+	np->scsi_mode = 0;
 	sym_nvram_setup_host(shost, np, nvram);
 
 	/*
@@ -857,33 +886,7 @@ static int sym_prepare_setting(struct Scsi_Host *shost, struct sym_hcb *np, stru
 	 */
 	sym_init_burst(np, burst_max);
 
-	/*
-	 *  Set SCSI BUS mode.
-	 *  - LVD capable chips (895/895A/896/1010) report the 
-	 *    current BUS mode through the STEST4 IO register.
-	 *  - For previous generation chips (825/825A/875), 
-	 *    user has to tell us how to check against HVD, 
-	 *    since a 100% safe algorithm is not possible.
-	 */
-	np->scsi_mode = SMODE_SE;
-	if (np->features & (FE_ULTRA2|FE_ULTRA3))
-		np->scsi_mode = (np->sv_stest4 & SMODE);
-	else if	(np->features & FE_DIFF) {
-		if (SYM_SETUP_SCSI_DIFF == 1) {
-			if (np->sv_scntl3) {
-				if (np->sv_stest2 & 0x20)
-					np->scsi_mode = SMODE_HVD;
-			}
-			else if (nvram->type == SYM_SYMBIOS_NVRAM) {
-				if (!(INB(np, nc_gpreg) & 0x08))
-					np->scsi_mode = SMODE_HVD;
-			}
-		}
-		else if	(SYM_SETUP_SCSI_DIFF == 2)
-			np->scsi_mode = SMODE_HVD;
-	}
-	if (np->scsi_mode == SMODE_HVD)
-		np->rv_stest2 |= 0x20;
+	sym_set_bus_mode(np, nvram);
 
 	/*
 	 *  Set LED support from SCRIPTS.