]> git.baikalelectronics.ru Git - kernel.git/commit
bnx2x: Fix statistics locking scheme
authorYuval Mintz <Yuval.Mintz@qlogic.com>
Mon, 23 Mar 2015 08:56:14 +0000 (10:56 +0200)
committerDavid S. Miller <davem@davemloft.net>
Tue, 24 Mar 2015 02:38:24 +0000 (22:38 -0400)
commit30f44f372dba2bf0b582773f78bfcb67d5fa99b0
tree0b69f6fbf728fb82dbf311c9b8bfc0ddaa2601b3
parent086c4df576145587d0b3a0b69674b88dcc914bb7
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>
drivers/net/ethernet/broadcom/bnx2x/bnx2x.h
drivers/net/ethernet/broadcom/bnx2x/bnx2x_main.c
drivers/net/ethernet/broadcom/bnx2x/bnx2x_sriov.c
drivers/net/ethernet/broadcom/bnx2x/bnx2x_stats.c
drivers/net/ethernet/broadcom/bnx2x/bnx2x_stats.h