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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>
This commit is contained in:
Stefan Richter 2008-10-26 11:04:20 +01:00
parent c82cdea1e1
commit 621f6dd715
1 changed files with 6 additions and 15 deletions
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21
drivers/firewire/fw-sbp2.c
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@ -670,17 +670,6 @@ static void sbp2_agent_reset_no_wait(struct sbp2_logical_unit *lu)
&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 @@ static void sbp2_login(struct work_struct *work)
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 @@ static void sbp2_login(struct work_struct *work)
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 @@ static void sbp2_reconnect(struct work_struct *work)
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 @@ static void sbp2_reconnect(struct work_struct *work)
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);