firewire: Implement gap count optimization.
Signed-off-by: Kristian Høgsberg <krh@redhat.com>
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/firewire/fw-card.c b/drivers/firewire/fw-card.c
index c8b7d69..307c8b8 100644
--- a/drivers/firewire/fw-card.c
+++ b/drivers/firewire/fw-card.c
@@ -186,14 +186,17 @@
}
EXPORT_SYMBOL(fw_core_remove_descriptor);
+static const char gap_count_table[] = {
+ 63, 5, 7, 8, 10, 13, 16, 18, 21, 24, 26, 29, 32, 35, 37, 40
+};
+
static void
fw_card_irm_work(struct work_struct *work)
{
- struct fw_card *card =
- container_of(work, struct fw_card, work.work);
+ struct fw_card *card = container_of(work, struct fw_card, work.work);
struct fw_device *root;
unsigned long flags;
- int new_irm_id, generation;
+ int root_id, new_irm_id, gap_count, generation, do_reset = 0;
/* FIXME: This simple bus management unconditionally picks a
* cycle master if the current root can't do it. We need to
@@ -206,35 +209,50 @@
generation = card->generation;
root = card->root_node->data;
+ root_id = card->root_node->node_id;
- if (root == NULL)
+ if (root == NULL) {
/* Either link_on is false, or we failed to read the
* config rom. In either case, pick another root. */
new_irm_id = card->local_node->node_id;
- else if (root->state != FW_DEVICE_RUNNING)
+ } else if (root->state != FW_DEVICE_RUNNING) {
/* If we haven't probed this device yet, bail out now
* and let's try again once that's done. */
- new_irm_id = -1;
- else if (root->config_rom[2] & bib_cmc)
+ new_irm_id = root_id;
+ } else if (root->config_rom[2] & bib_cmc) {
/* FIXME: I suppose we should set the cmstr bit in the
* STATE_CLEAR register of this node, as described in
* 1394-1995, 8.4.2.6. Also, send out a force root
* packet for this node. */
- new_irm_id = -1;
- else
+ new_irm_id = root_id;
+ } else {
/* Current root has an active link layer and we
* successfully read the config rom, but it's not
* cycle master capable. */
new_irm_id = card->local_node->node_id;
+ }
- if (card->irm_retries++ > 5)
- new_irm_id = -1;
+ /* Now figure out what gap count to set. */
+ if (card->topology_type == FW_TOPOLOGY_A &&
+ card->root_node->max_hops < ARRAY_SIZE(gap_count_table))
+ gap_count = gap_count_table[card->root_node->max_hops];
+ else
+ gap_count = 63;
+
+ /* Finally, figure out if we should do a reset or not. If we've
+ * done less that 5 resets with the same physical topology and we
+ * have either a new root or a new gap count setting, let's do it. */
+
+ if (card->irm_retries++ < 5 &&
+ (card->gap_count != gap_count || new_irm_id != root_id))
+ do_reset = 1;
spin_unlock_irqrestore(&card->lock, flags);
- if (new_irm_id > 0) {
- fw_notify("Trying to become root (card %d)\n", card->index);
- fw_send_force_root(card, new_irm_id, generation);
+ if (do_reset) {
+ fw_notify("phy config: card %d, new root=%x, gap_count=%d\n",
+ card->index, new_irm_id, gap_count);
+ fw_send_phy_config(card, new_irm_id, generation, gap_count);
fw_core_initiate_bus_reset(card, 1);
}
}
diff --git a/drivers/firewire/fw-topology.c b/drivers/firewire/fw-topology.c
index 684d87d..d3131e7 100644
--- a/drivers/firewire/fw-topology.c
+++ b/drivers/firewire/fw-topology.c
@@ -113,6 +113,44 @@
return node;
}
+/* Compute the maximum hop count for this node and it's children. The
+ * maximum hop count is the maximum number of connections between any
+ * two nodes in the subtree rooted at this node. We need this for
+ * setting the gap count. As we build the tree bottom up in
+ * build_tree() below, this is fairly easy to do: for each node we
+ * maintain the max hop count and the max depth, ie the number of hops
+ * to the furthest leaf. Computing the max hop count breaks down into
+ * two cases: either the path goes through this node, in which case
+ * the hop count is the sum of the two biggest child depths plus 2.
+ * Or it could be the case that the max hop path is entirely
+ * containted in a child tree, in which case the max hop count is just
+ * the max hop count of this child.
+ */
+static void update_hop_count(struct fw_node *node)
+{
+ int depths[2] = { -1, -1 };
+ int max_child_hops = 0;
+ int i;
+
+ for (i = 0; i < node->port_count; i++) {
+ if (node->ports[i].node == NULL)
+ continue;
+
+ if (node->ports[i].node->max_hops > max_child_hops)
+ max_child_hops = node->ports[i].node->max_hops;
+
+ if (node->ports[i].node->max_depth > depths[0]) {
+ depths[1] = depths[0];
+ depths[0] = node->ports[i].node->max_depth;
+ } else if (node->ports[i].node->max_depth > depths[1])
+ depths[1] = node->ports[i].node->max_depth;
+ }
+
+ node->max_depth = depths[0] + 1;
+ node->max_hops = max(max_child_hops, depths[0] + depths[1] + 2);
+}
+
+
/**
* build_tree - Build the tree representation of the topology
* @self_ids: array of self IDs to create the tree from
@@ -131,6 +169,7 @@
struct list_head stack, *h;
u32 *sid, *next_sid, *end, q;
int i, port_count, child_port_count, phy_id, parent_count, stack_depth;
+ int gap_count, topology_type;
local_node = NULL;
node = NULL;
@@ -140,6 +179,8 @@
end = sid + card->self_id_count;
phy_id = 0;
card->irm_node = NULL;
+ gap_count = self_id_gap_count(*sid);
+ topology_type = 0;
while (sid < end) {
next_sid = count_ports(sid, &port_count, &child_port_count);
@@ -179,6 +220,11 @@
if (self_id_contender(q))
card->irm_node = node;
+ if (node->phy_speed == SCODE_BETA)
+ topology_type |= FW_TOPOLOGY_B;
+ else
+ topology_type |= FW_TOPOLOGY_A;
+
parent_count = 0;
for (i = 0; i < port_count; i++) {
@@ -223,11 +269,21 @@
list_add_tail(&node->link, &stack);
stack_depth += 1 - child_port_count;
+ /* If all PHYs does not report the same gap count
+ * setting, we fall back to 63 which will force a gap
+ * count reconfiguration and a reset. */
+ if (self_id_gap_count(q) != gap_count)
+ gap_count = 63;
+
+ update_hop_count(node);
+
sid = next_sid;
phy_id++;
}
card->root_node = node;
+ card->gap_count = gap_count;
+ card->topology_type = topology_type;
return local_node;
}
@@ -286,7 +342,8 @@
int b_path = (node->phy_speed == SCODE_BETA);
if (parent != NULL) {
- node->max_speed = min(parent->max_speed, node->phy_speed);
+ node->max_speed = min((u8)parent->max_speed,
+ (u8)node->phy_speed);
node->b_path = parent->b_path && b_path;
} else {
node->max_speed = node->phy_speed;
@@ -329,7 +386,7 @@
* as we go.
*/
static void
-update_tree(struct fw_card *card, struct fw_node *root, int *changed)
+update_tree(struct fw_card *card, struct fw_node *root)
{
struct list_head list0, list1;
struct fw_node *node0, *node1;
@@ -342,7 +399,6 @@
node0 = fw_node(list0.next);
node1 = fw_node(list1.next);
- *changed = 0;
while (&node0->link != &list0) {
@@ -358,6 +414,7 @@
node0->color = card->color;
node0->link_on = node1->link_on;
node0->initiated_reset = node1->initiated_reset;
+ node0->max_hops = node1->max_hops;
node1->color = card->color;
fw_node_event(card, node0, event);
@@ -386,7 +443,6 @@
for_each_fw_node(card, node0->ports[i].node,
report_lost_node);
node0->ports[i].node = NULL;
- *changed = 1;
} else if (node1->ports[i].node) {
/* One or more node were connected to
* this port. Move the new nodes into
@@ -395,7 +451,6 @@
move_tree(node0, node1, i);
for_each_fw_node(card, node0->ports[i].node,
report_found_node);
- *changed = 1;
}
}
@@ -411,12 +466,17 @@
{
struct fw_node *local_node;
unsigned long flags;
- int changed;
fw_flush_transactions(card);
spin_lock_irqsave(&card->lock, flags);
+ /* If the new topology has a different self_id_count the topology
+ * changed, either nodes were added or removed. In that case we
+ * reset the IRM reset counter. */
+ if (card->self_id_count != self_id_count)
+ card->irm_retries = 0;
+
card->node_id = node_id;
card->self_id_count = self_id_count;
card->generation = generation;
@@ -433,9 +493,7 @@
card->local_node = local_node;
for_each_fw_node(card, local_node, report_found_node);
} else {
- update_tree(card, local_node, &changed);
- if (changed)
- card->irm_retries = 0;
+ update_tree(card, local_node);
}
/* If we're not the root node, we may have to do some IRM work. */
diff --git a/drivers/firewire/fw-topology.h b/drivers/firewire/fw-topology.h
index ab03059..f2a575e 100644
--- a/drivers/firewire/fw-topology.h
+++ b/drivers/firewire/fw-topology.h
@@ -23,6 +23,12 @@
#define __fw_topology_h
enum {
+ FW_TOPOLOGY_A = 0x01,
+ FW_TOPOLOGY_B = 0x02,
+ FW_TOPOLOGY_MIXED = 0x03,
+};
+
+enum {
FW_NODE_CREATED = 0x00,
FW_NODE_UPDATED = 0x01,
FW_NODE_DESTROYED = 0x02,
@@ -42,10 +48,11 @@
unsigned link_on : 1;
unsigned initiated_reset : 1;
unsigned b_path : 1;
- u8 phy_speed; /* As in the self ID packet. */
- u8 max_speed; /* Minimum of all phy-speeds and port speeds on
- * the path from the local node to this node. */
-
+ u8 phy_speed : 3; /* As in the self ID packet. */
+ u8 max_speed : 5; /* Minimum of all phy-speeds and port speeds on
+ * the path from the local node to this node. */
+ u8 max_depth : 4; /* Maximum depth to any leaf node */
+ u8 max_hops : 4; /* Max hops in this sub tree */
atomic_t ref_count;
/* For serializing node topology into a list. */
diff --git a/drivers/firewire/fw-transaction.c b/drivers/firewire/fw-transaction.c
index 439a3e3..57ecf95 100644
--- a/drivers/firewire/fw-transaction.c
+++ b/drivers/firewire/fw-transaction.c
@@ -274,11 +274,15 @@
card->driver->send_request(card, packet);
}
-void fw_send_force_root(struct fw_card *card, int node_id, int generation)
+void fw_send_phy_config(struct fw_card *card,
+ int node_id, int generation, int gap_count)
{
u32 q;
- q = phy_identifier(PHY_PACKET_CONFIG) | phy_config_root_id(node_id);
+ q = phy_identifier(PHY_PACKET_CONFIG) |
+ phy_config_root_id(node_id) |
+ phy_config_gap_count(gap_count);
+
send_phy_packet(card, q, generation);
}
diff --git a/drivers/firewire/fw-transaction.h b/drivers/firewire/fw-transaction.h
index 22d2871..df65245 100644
--- a/drivers/firewire/fw-transaction.h
+++ b/drivers/firewire/fw-transaction.h
@@ -259,6 +259,8 @@
struct fw_node *root_node;
struct fw_node *irm_node;
int color;
+ int gap_count;
+ int topology_type;
int index;
@@ -386,8 +388,8 @@
void fw_flush_transactions(struct fw_card *card);
-void
-fw_send_force_root(struct fw_card *card, int node_id, int generation);
+void fw_send_phy_config(struct fw_card *card,
+ int node_id, int generation, int gap_count);
/* Called by the topology code to inform the device code of node
* activity; found, lost, or updated nodes */
