bnx2x: Fix statistics locking scheme

Statistics' state-machine in bnx2x driver must be synced with various driver
flows, but its current locking scheme manages to be wasteful [using 2 locks +
additional local variable] and prone to race-conditions at the same time,
as the state-machine and 'action' are being accessed under different locks.

In addition, current 'safe exec' isn't in fact safe, since the only guarantee
it gives is that DMA transactions are over, but ramrods might still be running.

This patch cleans up said logic, leaving us with a single lock for the entire
flow and removing the possible races.

Changes from v2:
	- Switched into mutex locking from semaphore locking.
	- Release locks on error flows.

Changes from v1:
	Failure to acquire lock fails flow instead of printing a warning and
	allowing access to the critical section.

Signed-off-by: Yuval Mintz <Yuval.Mintz@qlogic.com>
Signed-off-by: Ariel Elior <Ariel.Elior@qlogic.com>
Signed-off-by: David S. Miller <davem@davemloft.net>

1 files changed, 1 insertions, 3 deletions

diff --git a/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h b/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h
index 756053c028be..4085c4b31047 100644
--- a/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h
+++ b/drivers/net/ethernet/broadcom/bnx2x/bnx2x.h
@@ -1811,7 +1811,7 @@ struct bnx2x {
 	int			stats_state;
 
 	/* used for synchronization of concurrent threads statistics handling */
-	spinlock_t		stats_lock;
+	struct mutex		stats_lock;
 
 	/* used by dmae command loader */
 	struct dmae_command	stats_dmae;
@@ -1935,8 +1935,6 @@ struct bnx2x {
 
 	int fp_array_size;
 	u32 dump_preset_idx;
-	bool					stats_started;
-	struct semaphore			stats_sema;
 
 	u8					phys_port_id[ETH_ALEN];