ieee1394: resume remote ports when starting a host (fixes device recognition)

After initializing an IEEE 1394 host, broadcast a resume packet.  This makes
remote nodes visible which suspended their ports while the host was down.
Such nodes had to be unplugged and replugged in order to be recognized.

Motorola DCT6200 cable reciever was affected, probably other devices too.
http://marc.theaimsgroup.com/?t=113202715800001

Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
Signed-off-by: Jody McIntyre <scjody@modernduck.com>

2 files changed, 26 insertions, 0 deletions

diff --git a/drivers/ieee1394/hosts.h b/drivers/ieee1394/hosts.h
index 38f42112dff0..ae9b02cc013f 100644
--- a/drivers/ieee1394/hosts.h
+++ b/drivers/ieee1394/hosts.h
@@ -41,6 +41,7 @@ struct hpsb_host {
         /* this nodes state */
         unsigned in_bus_reset:1;
         unsigned is_shutdown:1;
+        unsigned resume_packet_sent:1;
 
         /* this nodes' duties on the bus */
         unsigned is_root:1;
diff --git a/drivers/ieee1394/nodemgr.c b/drivers/ieee1394/nodemgr.c
index 3f0917bbd7f5..b56934edd62b 100644
--- a/drivers/ieee1394/nodemgr.c
+++ b/drivers/ieee1394/nodemgr.c
@@ -1410,6 +1410,24 @@ static void nodemgr_node_probe(struct host_info *hi, int generation)
         return;
 }
 
+static int nodemgr_send_resume_packet(struct hpsb_host *host)
+{
+        struct hpsb_packet *packet;
+        int ret = 1;
+
+        packet = hpsb_make_phypacket(host,
+                        0x003c0000 | NODEID_TO_NODE(host->node_id) << 24);
+        if (packet) {
+                packet->no_waiter = 1;
+                packet->generation = get_hpsb_generation(host);
+                ret = hpsb_send_packet(packet);
+        }
+        if (ret)
+                HPSB_WARN("fw-host%d: Failed to broadcast resume packet",
+                          host->id);
+        return ret;
+}
+
 /* Because we are a 1394a-2000 compliant IRM, we need to inform all the other
  * nodes of the broadcast channel.  (Really we're only setting the validity
  * bit). Other IRM responsibilities go in here as well. */
@@ -1460,6 +1478,13 @@ static int nodemgr_do_irm_duties(struct hpsb_host *host, int cycles)
                 }
         }
 
+        /* Some devices suspend their ports while being connected to an inactive
+         * host adapter, i.e. if connected before the low-level driver is
+         * loaded.  They become visible either when physically unplugged and
+         * replugged, or when receiving a resume packet.  Send one once. */
+        if (!host->resume_packet_sent && !nodemgr_send_resume_packet(host))
+                host->resume_packet_sent = 1;
+
         return 1;
 }