rt2x00: Fix race conditions in flag handling
Some of the flags should be accessed atomically to
prevent race conditions. The flags that are most important
are those that can change often and indicate the actual
state of the device, queue or queue entry.
The big flag rename was done to move all state flags to
the same naming type as the other rt2x00dev flags and
made sure all places where the flags were used were changed. ;)
Thanks to Stephen for most of the queue flags updates,
which fixes some of the most obvious consequences of the
race conditions. Among those the notorious:
rt2x00queue_write_tx_frame: Error - Arrived at non-free entry in the non-full queue 0.
rt2x00queue_write_tx_frame: Error - Arrived at non-free entry in the non-full queue 0.
rt2x00queue_write_tx_frame: Error - Arrived at non-free entry in the non-full queue 0.
Signed-off-by: Stephen Blackheath <tramp.enshrine.stephen@blacksapphire.com>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/rt2x00/rt2x00dev.c b/drivers/net/wireless/rt2x00/rt2x00dev.c
index 328ff8b..330ab77 100644
--- a/drivers/net/wireless/rt2x00/rt2x00dev.c
+++ b/drivers/net/wireless/rt2x00/rt2x00dev.c
@@ -34,7 +34,7 @@
*/
void rt2x00lib_reset_link_tuner(struct rt2x00_dev *rt2x00dev)
{
- if (!test_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags))
+ if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
return;
/*
@@ -94,8 +94,8 @@
* Don't enable the radio twice.
* And check if the hardware button has been disabled.
*/
- if (test_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags) ||
- test_bit(DEVICE_DISABLED_RADIO_HW, &rt2x00dev->flags))
+ if (test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags) ||
+ test_bit(DEVICE_STATE_DISABLED_RADIO_HW, &rt2x00dev->flags))
return 0;
/*
@@ -117,7 +117,7 @@
rt2x00leds_led_radio(rt2x00dev, true);
rt2x00led_led_activity(rt2x00dev, true);
- __set_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags);
+ set_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags);
/*
* Enable RX.
@@ -134,7 +134,7 @@
void rt2x00lib_disable_radio(struct rt2x00_dev *rt2x00dev)
{
- if (!__test_and_clear_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags))
+ if (!test_and_clear_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
return;
/*
@@ -354,7 +354,7 @@
* When the radio is shutting down we should
* immediately cease all link tuning.
*/
- if (!test_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags))
+ if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
return;
/*
@@ -431,7 +431,7 @@
* note that in the spinlock protected area above the delayed_flags
* have been cleared correctly.
*/
- if (!test_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags))
+ if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
return;
if (delayed_flags & DELAYED_UPDATE_BEACON)
@@ -484,7 +484,7 @@
void rt2x00lib_beacondone(struct rt2x00_dev *rt2x00dev)
{
- if (!test_bit(DEVICE_ENABLED_RADIO, &rt2x00dev->flags))
+ if (!test_bit(DEVICE_STATE_ENABLED_RADIO, &rt2x00dev->flags))
return;
ieee80211_iterate_active_interfaces_atomic(rt2x00dev->hw,
@@ -572,7 +572,7 @@
rt2x00dev->ops->lib->init_txentry(rt2x00dev, entry);
- __clear_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
+ clear_bit(ENTRY_OWNER_DEVICE_DATA, &entry->flags);
rt2x00queue_index_inc(entry->queue, Q_INDEX_DONE);
/*
@@ -888,7 +888,7 @@
static void rt2x00lib_remove_hw(struct rt2x00_dev *rt2x00dev)
{
- if (test_bit(DEVICE_REGISTERED_HW, &rt2x00dev->flags))
+ if (test_bit(DEVICE_STATE_REGISTERED_HW, &rt2x00dev->flags))
ieee80211_unregister_hw(rt2x00dev->hw);
if (likely(rt2x00dev->hw->wiphy->bands[IEEE80211_BAND_2GHZ])) {
@@ -906,6 +906,9 @@
struct hw_mode_spec *spec = &rt2x00dev->spec;
int status;
+ if (test_bit(DEVICE_STATE_REGISTERED_HW, &rt2x00dev->flags))
+ return 0;
+
/*
* Initialize HW modes.
*/
@@ -927,7 +930,7 @@
return status;
}
- __set_bit(DEVICE_REGISTERED_HW, &rt2x00dev->flags);
+ set_bit(DEVICE_STATE_REGISTERED_HW, &rt2x00dev->flags);
return 0;
}
@@ -937,7 +940,7 @@
*/
static void rt2x00lib_uninitialize(struct rt2x00_dev *rt2x00dev)
{
- if (!__test_and_clear_bit(DEVICE_INITIALIZED, &rt2x00dev->flags))
+ if (!test_and_clear_bit(DEVICE_STATE_INITIALIZED, &rt2x00dev->flags))
return;
/*
@@ -960,7 +963,7 @@
{
int status;
- if (test_bit(DEVICE_INITIALIZED, &rt2x00dev->flags))
+ if (test_bit(DEVICE_STATE_INITIALIZED, &rt2x00dev->flags))
return 0;
/*
@@ -979,7 +982,7 @@
return status;
}
- __set_bit(DEVICE_INITIALIZED, &rt2x00dev->flags);
+ set_bit(DEVICE_STATE_INITIALIZED, &rt2x00dev->flags);
/*
* Register the extra components.
@@ -993,7 +996,7 @@
{
int retval;
- if (test_bit(DEVICE_STARTED, &rt2x00dev->flags))
+ if (test_bit(DEVICE_STATE_STARTED, &rt2x00dev->flags))
return 0;
/*
@@ -1024,15 +1027,15 @@
rt2x00dev->intf_sta_count = 0;
rt2x00dev->intf_associated = 0;
- __set_bit(DEVICE_STARTED, &rt2x00dev->flags);
- __set_bit(DEVICE_DIRTY_CONFIG, &rt2x00dev->flags);
+ set_bit(DEVICE_STATE_STARTED, &rt2x00dev->flags);
+ set_bit(DEVICE_STATE_DIRTY_CONFIG, &rt2x00dev->flags);
return 0;
}
void rt2x00lib_stop(struct rt2x00_dev *rt2x00dev)
{
- if (!test_bit(DEVICE_STARTED, &rt2x00dev->flags))
+ if (!test_and_clear_bit(DEVICE_STATE_STARTED, &rt2x00dev->flags))
return;
/*
@@ -1044,8 +1047,6 @@
rt2x00dev->intf_ap_count = 0;
rt2x00dev->intf_sta_count = 0;
rt2x00dev->intf_associated = 0;
-
- __clear_bit(DEVICE_STARTED, &rt2x00dev->flags);
}
/*
@@ -1100,7 +1101,7 @@
rt2x00rfkill_allocate(rt2x00dev);
rt2x00debug_register(rt2x00dev);
- __set_bit(DEVICE_PRESENT, &rt2x00dev->flags);
+ set_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags);
return 0;
@@ -1113,7 +1114,7 @@
void rt2x00lib_remove_dev(struct rt2x00_dev *rt2x00dev)
{
- __clear_bit(DEVICE_PRESENT, &rt2x00dev->flags);
+ clear_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags);
/*
* Disable radio.
@@ -1158,14 +1159,15 @@
int retval;
NOTICE(rt2x00dev, "Going to sleep.\n");
- __clear_bit(DEVICE_PRESENT, &rt2x00dev->flags);
/*
* Only continue if mac80211 has open interfaces.
*/
- if (!test_bit(DEVICE_STARTED, &rt2x00dev->flags))
+ if (!test_and_clear_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags) ||
+ !test_bit(DEVICE_STATE_STARTED, &rt2x00dev->flags))
goto exit;
- __set_bit(DEVICE_STARTED_SUSPEND, &rt2x00dev->flags);
+
+ set_bit(DEVICE_STATE_STARTED_SUSPEND, &rt2x00dev->flags);
/*
* Disable radio.
@@ -1237,7 +1239,7 @@
/*
* Only continue if mac80211 had open interfaces.
*/
- if (!__test_and_clear_bit(DEVICE_STARTED_SUSPEND, &rt2x00dev->flags))
+ if (!test_and_clear_bit(DEVICE_STATE_STARTED_SUSPEND, &rt2x00dev->flags))
return 0;
/*
@@ -1264,7 +1266,7 @@
/*
* We are ready again to receive requests from mac80211.
*/
- __set_bit(DEVICE_PRESENT, &rt2x00dev->flags);
+ set_bit(DEVICE_STATE_PRESENT, &rt2x00dev->flags);
/*
* It is possible that during that mac80211 has attempted
@@ -1284,7 +1286,7 @@
return 0;
exit:
- rt2x00lib_disable_radio(rt2x00dev);
+ rt2x00lib_stop(rt2x00dev);
rt2x00lib_uninitialize(rt2x00dev);
rt2x00debug_deregister(rt2x00dev);