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authorTim Gardner <timg@tpi.com>2011-04-20 09:00:49 +0000
committerGreg Kroah-Hartman <gregkh@suse.de>2011-05-09 15:06:38 -0700
commitb000ec13075615ace30250ab6e355a3f0c956735 (patch)
treeca897ac53ab025779def9bd00b1f8b39ceb045c3 /drivers
parent40b2b978ebc16d96805c8330883967a0ca8aedf9 (diff)
downloadlinux-linaro-android-b000ec13075615ace30250ab6e355a3f0c956735.tar.gz
atl1c: Fix work event interrupt/task races
commit cb771838715b1c470bc5735bdae709b33b18e0ad upstream. The mechanism used to initiate work events from the interrupt handler has a classic read/modify/write race between the interrupt handler that sets the condition, and the worker task that reads and clears the condition. Close these races by using atomic bit fields. Cc: Jie Yang <jie.yang@atheros.com> Signed-off-by: Tim Gardner <tim.gardner@canonical.com> Signed-off-by: David S. Miller <davem@davemloft.net> Signed-off-by: Greg Kroah-Hartman <gregkh@suse.de>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/net/atl1c/atl1c.h6
-rw-r--r--drivers/net/atl1c/atl1c_main.c14
2 files changed, 8 insertions, 12 deletions
diff --git a/drivers/net/atl1c/atl1c.h b/drivers/net/atl1c/atl1c.h
index 9ab58097fa2..dec81102adc 100644
--- a/drivers/net/atl1c/atl1c.h
+++ b/drivers/net/atl1c/atl1c.h
@@ -566,9 +566,9 @@ struct atl1c_adapter {
#define __AT_TESTING 0x0001
#define __AT_RESETTING 0x0002
#define __AT_DOWN 0x0003
- u8 work_event;
-#define ATL1C_WORK_EVENT_RESET 0x01
-#define ATL1C_WORK_EVENT_LINK_CHANGE 0x02
+ unsigned long work_event;
+#define ATL1C_WORK_EVENT_RESET 0
+#define ATL1C_WORK_EVENT_LINK_CHANGE 1
u32 msg_enable;
bool have_msi;
diff --git a/drivers/net/atl1c/atl1c_main.c b/drivers/net/atl1c/atl1c_main.c
index 3824382faec..dffc7f72e7d 100644
--- a/drivers/net/atl1c/atl1c_main.c
+++ b/drivers/net/atl1c/atl1c_main.c
@@ -325,7 +325,7 @@ static void atl1c_link_chg_event(struct atl1c_adapter *adapter)
}
}
- adapter->work_event |= ATL1C_WORK_EVENT_LINK_CHANGE;
+ set_bit(ATL1C_WORK_EVENT_LINK_CHANGE, &adapter->work_event);
schedule_work(&adapter->common_task);
}
@@ -337,20 +337,16 @@ static void atl1c_common_task(struct work_struct *work)
adapter = container_of(work, struct atl1c_adapter, common_task);
netdev = adapter->netdev;
- if (adapter->work_event & ATL1C_WORK_EVENT_RESET) {
- adapter->work_event &= ~ATL1C_WORK_EVENT_RESET;
+ if (test_and_clear_bit(ATL1C_WORK_EVENT_RESET, &adapter->work_event)) {
netif_device_detach(netdev);
atl1c_down(adapter);
atl1c_up(adapter);
netif_device_attach(netdev);
- return;
}
- if (adapter->work_event & ATL1C_WORK_EVENT_LINK_CHANGE) {
- adapter->work_event &= ~ATL1C_WORK_EVENT_LINK_CHANGE;
+ if (test_and_clear_bit(ATL1C_WORK_EVENT_LINK_CHANGE,
+ &adapter->work_event))
atl1c_check_link_status(adapter);
- }
- return;
}
@@ -369,7 +365,7 @@ static void atl1c_tx_timeout(struct net_device *netdev)
struct atl1c_adapter *adapter = netdev_priv(netdev);
/* Do the reset outside of interrupt context */
- adapter->work_event |= ATL1C_WORK_EVENT_RESET;
+ set_bit(ATL1C_WORK_EVENT_RESET, &adapter->work_event);
schedule_work(&adapter->common_task);
}