Commit cb771838 authored by Tim Gardner's avatar Tim Gardner Committed by David S. Miller
Browse files

atl1c: Fix work event interrupt/task races



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: stable@kernel.org
Cc: Jie Yang <jie.yang@atheros.com>
Signed-off-by: default avatarTim Gardner <tim.gardner@canonical.com>
Signed-off-by: default avatarDavid S. Miller <davem@davemloft.net>
parent e74fbd03
......@@ -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;
......
......@@ -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);
}
......
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