firewire: fw-sbp2: remove unnecessary locking
What was I thinking when I added sbp2_set_generation()? Its locking did
nothing (except for implicitly providing the necessary barrier between
node IDs update and generation update).
Signed-off-by: Stefan Richter <stefanr@s5r6.in-berlin.de>
diff --git a/drivers/firewire/fw-sbp2.c b/drivers/firewire/fw-sbp2.c
index e54403e..e88d506 100644
--- a/drivers/firewire/fw-sbp2.c
+++ b/drivers/firewire/fw-sbp2.c
@@ -670,17 +670,6 @@
&d, sizeof(d), complete_agent_reset_write_no_wait, t);
}
-static void sbp2_set_generation(struct sbp2_logical_unit *lu, int generation)
-{
- struct fw_card *card = fw_device(lu->tgt->unit->device.parent)->card;
- unsigned long flags;
-
- /* serialize with comparisons of lu->generation and card->generation */
- spin_lock_irqsave(&card->lock, flags);
- lu->generation = generation;
- spin_unlock_irqrestore(&card->lock, flags);
-}
-
static inline void sbp2_allow_block(struct sbp2_logical_unit *lu)
{
/*
@@ -884,7 +873,7 @@
goto out;
generation = device->generation;
- smp_rmb(); /* node_id must not be older than generation */
+ smp_rmb(); /* node IDs must not be older than generation */
node_id = device->node_id;
local_node_id = device->card->node_id;
@@ -908,7 +897,8 @@
tgt->node_id = node_id;
tgt->address_high = local_node_id << 16;
- sbp2_set_generation(lu, generation);
+ smp_wmb(); /* node IDs must not be older than generation */
+ lu->generation = generation;
lu->command_block_agent_address =
((u64)(be32_to_cpu(response.command_block_agent.high) & 0xffff)
@@ -1201,7 +1191,7 @@
goto out;
generation = device->generation;
- smp_rmb(); /* node_id must not be older than generation */
+ smp_rmb(); /* node IDs must not be older than generation */
node_id = device->node_id;
local_node_id = device->card->node_id;
@@ -1228,7 +1218,8 @@
tgt->node_id = node_id;
tgt->address_high = local_node_id << 16;
- sbp2_set_generation(lu, generation);
+ smp_wmb(); /* node IDs must not be older than generation */
+ lu->generation = generation;
fw_notify("%s: reconnected to LUN %04x (%d retries)\n",
tgt->bus_id, lu->lun, lu->retries);