2008-11-29 17:57:15

by Stefan Richter

Subject: [PATCH] firewire: fix resetting of bus manager retry counter

An earlier change, maybe long ago, removed the copying of self_id_count
into card->self_id_count. Since then each bus reset cleared
card->bm_retries even when it shouldn't.

Signed-off-by: Stefan Richter <[email protected]>
---
drivers/firewire/fw-topology.c | 14 ++++++--------
drivers/firewire/fw-transaction.h | 1 -
2 files changed, 6 insertions(+), 9 deletions(-)

Index: linux/drivers/firewire/fw-topology.c
===================================================================
--- linux.orig/drivers/firewire/fw-topology.c
+++ linux/drivers/firewire/fw-topology.c
@@ -355,6 +355,9 @@ report_lost_node(struct fw_card *card,
{
fw_node_event(card, node, FW_NODE_DESTROYED);
fw_node_put(node);
+
+ /* Topology has changed - reset bus manager retry counter */
+ card->bm_retries = 0;
}

static void
@@ -374,6 +377,9 @@ report_found_node(struct fw_card *card,
}

fw_node_event(card, node, FW_NODE_CREATED);
+
+ /* Topology has changed - reset bus manager retry counter */
+ card->bm_retries = 0;
}

void fw_destroy_nodes(struct fw_card *card)
@@ -526,14 +532,6 @@ fw_core_handle_bus_reset(struct fw_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->bm_retries = 0;
-
card->node_id = node_id;
/*
* Update node_id before generation to prevent anybody from using
Index: linux/drivers/firewire/fw-transaction.h
===================================================================
--- linux.orig/drivers/firewire/fw-transaction.h
+++ linux/drivers/firewire/fw-transaction.h
@@ -239,7 +239,6 @@ struct fw_card {
* We need to store up to 4 self ID for a maximum of 63
* devices plus 3 words for the topology map header.
*/
- int self_id_count;
u32 topology_map[252 + 3];
u32 broadcast_channel;


--
Stefan Richter
-=====-==--- =-== ===-=
http://arcgraph.de/sr/

2008-11-29 18:01:18

by Stefan Richter

Subject: [PATCH] firewire: reorder struct fw_card for better cache efficiency

topology_map is by far the largest member in struct fw_card. Move it to
the very end of the struct so that card pointer dereferences have better
chances to hit the CPU cache.

This requires to increase the topology_map backing store to the size
specified in IEEE 1394, i.e. 256 rather than 255 quadlets. Otherwise
the topology_map response handler may access invalid memory.

Signed-off-by: Stefan Richter <[email protected]>
---
drivers/firewire/fw-transaction.h | 10 +++-------
1 file changed, 3 insertions(+), 7 deletions(-)

Index: linux/drivers/firewire/fw-transaction.h
===================================================================
--- linux.orig/drivers/firewire/fw-transaction.h
+++ linux/drivers/firewire/fw-transaction.h
@@ -235,13 +235,6 @@ struct fw_card {
int link_speed;
int config_rom_generation;

- /*
- * We need to store up to 4 self ID for a maximum of 63
- * devices plus 3 words for the topology map header.
- */
- u32 topology_map[252 + 3];
- u32 broadcast_channel;
-
spinlock_t lock; /* Take this lock when handling the lists in
* this struct. */
struct fw_node *local_node;
@@ -259,6 +252,9 @@ struct fw_card {
struct delayed_work work;
int bm_retries;
int bm_generation;
+
+ u32 broadcast_channel;
+ u32 topology_map[(CSR_TOPOLOGY_MAP_END - CSR_TOPOLOGY_MAP) / 4];
};

static inline struct fw_card *fw_card_get(struct fw_card *card)

--
Stefan Richter
-=====-==--- =-== ===-=
http://arcgraph.de/sr/