bcma: fix handling of big addrl

The return value of bcma_erom_get_addr_desc() is a unsigned value and it
could wrap around in the two complement writing. This happens for one
core in the BCM4708 SoC.
Signed-off-by: NHauke Mehrtens <hauke@hauke-m.de>
Signed-off-by: NJohn W. Linville <linville@tuxdriver.com>

drivers/bcma/scan.c

@@ -213,7 +213,7 @@ static s32 bcma_erom_get_mst_port(struct bcma_bus *bus, u32 __iomem **eromptr)
 	return ent;
 }
 
-static s32 bcma_erom_get_addr_desc(struct bcma_bus *bus, u32 __iomem **eromptr,
+static u32 bcma_erom_get_addr_desc(struct bcma_bus *bus, u32 __iomem **eromptr,
 				  u32 type, u8 port)
 {
 	u32 addrl, addrh, sizel, sizeh = 0;
@@ -225,7 +225,7 @@ static s32 bcma_erom_get_addr_desc(struct bcma_bus *bus, u32 __iomem **eromptr,
 	    ((ent & SCAN_ADDR_TYPE) != type) ||
 	    (((ent & SCAN_ADDR_PORT) >> SCAN_ADDR_PORT_SHIFT) != port)) {
 		bcma_erom_push_ent(eromptr);
-		return -EINVAL;
+		return (u32)-EINVAL;
 	}
 
 	addrl = ent & SCAN_ADDR_ADDR;
@@ -273,7 +273,7 @@ static int bcma_get_next_core(struct bcma_bus *bus, u32 __iomem **eromptr,
 			      struct bcma_device_id *match, int core_num,
 			      struct bcma_device *core)
 {
-	s32 tmp;
+	u32 tmp;
 	u8 i, j;
 	s32 cia, cib;
 	u8 ports[2], wrappers[2];
@@ -351,11 +351,11 @@ static int bcma_get_next_core(struct bcma_bus *bus, u32 __iomem **eromptr,
 	 * the main register space for the core
 	 */
 	tmp = bcma_erom_get_addr_desc(bus, eromptr, SCAN_ADDR_TYPE_SLAVE, 0);
-	if (tmp <= 0) {
+	if (tmp == 0 || IS_ERR_VALUE(tmp)) {
 		/* Try again to see if it is a bridge */
 		tmp = bcma_erom_get_addr_desc(bus, eromptr,
 					      SCAN_ADDR_TYPE_BRIDGE, 0);
-		if (tmp <= 0) {
+		if (tmp == 0 || IS_ERR_VALUE(tmp)) {
 			return -EILSEQ;
 		} else {
 			bcma_info(bus, "Bridge found\n");
@@ -369,7 +369,7 @@ static int bcma_get_next_core(struct bcma_bus *bus, u32 __iomem **eromptr,
 		for (j = 0; ; j++) {
 			tmp = bcma_erom_get_addr_desc(bus, eromptr,
 				SCAN_ADDR_TYPE_SLAVE, i);
-			if (tmp < 0) {
+			if (IS_ERR_VALUE(tmp)) {
 				/* no more entries for port _i_ */
 				/* pr_debug("erom: slave port %d "
 				 * "has %d descriptors\n", i, j); */
@@ -386,7 +386,7 @@ static int bcma_get_next_core(struct bcma_bus *bus, u32 __iomem **eromptr,
 		for (j = 0; ; j++) {
 			tmp = bcma_erom_get_addr_desc(bus, eromptr,
 				SCAN_ADDR_TYPE_MWRAP, i);
-			if (tmp < 0) {
+			if (IS_ERR_VALUE(tmp)) {
 				/* no more entries for port _i_ */
 				/* pr_debug("erom: master wrapper %d "
 				 * "has %d descriptors\n", i, j); */
@@ -404,7 +404,7 @@ static int bcma_get_next_core(struct bcma_bus *bus, u32 __iomem **eromptr,
 		for (j = 0; ; j++) {
 			tmp = bcma_erom_get_addr_desc(bus, eromptr,
 				SCAN_ADDR_TYPE_SWRAP, i + hack);
-			if (tmp < 0) {
+			if (IS_ERR_VALUE(tmp)) {
 				/* no more entries for port _i_ */
 				/* pr_debug("erom: master wrapper %d "
 				 * has %d descriptors\n", i, j); */