firewire: fw-sbp2: increase login orb reply timeout, fix "failed to login"

Increase (and rename) the login orb reply timeout value to 20s
to match that of the old firewire stack. 2s simply didn't give
many devices enough time to spin up and reply.

Fixes inability to recognize some devices.
Failure mode was "orb reply timed out"/"failed to login".
Signed-off-by: Jarod Wilson <jwilson@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de> (style, comments, changelog)

drivers/firewire/fw-sbp2.c

@@ -151,9 +151,16 @@ struct sbp2_target {
 	struct list_head lu_list;
 };
 
-#define SBP2_MAX_SG_ELEMENT_LENGTH	0xf000
+/*
+ * Per section 7.4.8 of the SBP-2 spec, a mgt_ORB_timeout value can be
+ * provided in the config rom.  A high timeout value really only matters
+ * on initial login, where we'll just use 20s rather than hassling with
+ * reading the config rom, since it really wouldn't buy us much.
+ */
+#define SBP2_LOGIN_ORB_TIMEOUT		20000	/* Timeout in ms */
 #define SBP2_ORB_TIMEOUT		2000	/* Timeout in ms */
 #define SBP2_ORB_NULL			0x80000000
+#define SBP2_MAX_SG_ELEMENT_LENGTH	0xf000
 
 #define SBP2_DIRECTION_TO_MEDIA		0x0
 #define SBP2_DIRECTION_FROM_MEDIA	0x1
@@ -488,6 +495,7 @@ sbp2_send_management_orb(struct sbp2_logical_unit *lu, int node_id,
 {
 	struct fw_device *device = fw_device(lu->tgt->unit->device.parent);
 	struct sbp2_management_orb *orb;
+	unsigned int timeout;
 	int retval = -ENOMEM;
 
 	orb = kzalloc(sizeof(*orb), GFP_ATOMIC);
@@ -519,6 +527,9 @@ sbp2_send_management_orb(struct sbp2_logical_unit *lu, int node_id,
 		orb->request.misc |=
 			MANAGEMENT_ORB_RECONNECT(2) |
 			MANAGEMENT_ORB_EXCLUSIVE(sbp2_param_exclusive_login);
+		timeout = SBP2_LOGIN_ORB_TIMEOUT;
+	} else {
+		timeout = SBP2_ORB_TIMEOUT;
 	}
 
 	fw_memcpy_to_be32(&orb->request, &orb->request, sizeof(orb->request));
@@ -535,8 +546,7 @@ sbp2_send_management_orb(struct sbp2_logical_unit *lu, int node_id,
 	sbp2_send_orb(&orb->base, lu, node_id, generation,
 		      lu->tgt->management_agent_address);
 
-	wait_for_completion_timeout(&orb->done,
-				    msecs_to_jiffies(SBP2_ORB_TIMEOUT));
+	wait_for_completion_timeout(&orb->done, msecs_to_jiffies(timeout));
 
 	retval = -EIO;
 	if (sbp2_cancel_orbs(lu) == 0) {