[PATCH] ieee1394: fix cosmetic problem in speed probe

If ieee1394.h::IEEE1394_SPEED_MAX is bigger than the actual speed of an
1394b host adapter and the speed to another 1394b node was probed, a
bigger speed than actually used was kept in host->speed[n].  The only
resulting problem so far was sbp2 displaying bogus values in the syslog,
e.g. S3200 for actual S800 connections if IEEE1394_SPEED_MAX was S3200.
But other high-level drivers which access this field could get into more
trouble.  (Eth1394 is the only other in-tree driver which does so.  It
seems it is not affected.)

Nodemgr now clips this value according to the host adapter's link speed.

A pointer expression in nodemgr_check_speed is also changed for clarity.

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Ben Collins <bcollins@ubuntu.com>

drivers/ieee1394/nodemgr.c

@@ -71,7 +71,7 @@ static int nodemgr_check_speed(struct nodemgr_csr_info *ci, u64 addr,
 	u8 i, *speed, old_speed, good_speed;
 	int ret;
 
-	speed = ci->host->speed + NODEID_TO_NODE(ci->nodeid);
+	speed = &(ci->host->speed[NODEID_TO_NODE(ci->nodeid)]);
 	old_speed = *speed;
 	good_speed = IEEE1394_SPEED_MAX + 1;
 
@@ -1251,6 +1251,7 @@ static void nodemgr_node_scan_one(struct host_info *hi,
 	octlet_t guid;
 	struct csr1212_csr *csr;
 	struct nodemgr_csr_info *ci;
+	u8 *speed;
 
 	ci = kmalloc(sizeof(*ci), GFP_KERNEL);
 	if (!ci)
@@ -1259,8 +1260,12 @@ static void nodemgr_node_scan_one(struct host_info *hi,
 	ci->host = host;
 	ci->nodeid = nodeid;
 	ci->generation = generation;
-	ci->speed_unverified =
-		host->speed[NODEID_TO_NODE(nodeid)] > IEEE1394_SPEED_100;
+
+	/* Prepare for speed probe which occurs when reading the ROM */
+	speed = &(host->speed[NODEID_TO_NODE(nodeid)]);
+	if (*speed > host->csr.lnk_spd)
+		*speed = host->csr.lnk_spd;
+	ci->speed_unverified = *speed > IEEE1394_SPEED_100;
 
 	/* We need to detect when the ConfigROM's generation has changed,
 	 * so we only update the node's info when it needs to be.  */
@@ -1300,8 +1305,6 @@ static void nodemgr_node_scan_one(struct host_info *hi,
 		nodemgr_create_node(guid, csr, hi, nodeid, generation);
 	else
 		nodemgr_update_node(ne, csr, hi, nodeid, generation);
-
-	return;
 }