iwlegacy: fix channel switch locking
We use priv->mutex to avoid race conditions between chswitch_done()
and mac_channel_switch(), when marking channel switch in
progress. But chswitch_done() can be called in atomic context
from rx_csa() or with mutex already taken from commit_rxon().
To fix remove mutex from chswitch_done() and use atomic bitops
for marking channel switch pending.
Cc: stable@kernel.org # 2.6.39+
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/iwlegacy/iwl-4965.c b/drivers/net/wireless/iwlegacy/iwl-4965.c
index e1b8922..facc94e 100644
--- a/drivers/net/wireless/iwlegacy/iwl-4965.c
+++ b/drivers/net/wireless/iwlegacy/iwl-4965.c
@@ -1218,10 +1218,10 @@
* receive commit_rxon request
* abort any previous channel switch if still in process
*/
- if (priv->switch_rxon.switch_in_progress &&
- (priv->switch_rxon.channel != ctx->staging.channel)) {
+ if (test_bit(STATUS_CHANNEL_SWITCH_PENDING, &priv->status) &&
+ (priv->switch_channel != ctx->staging.channel)) {
IWL_DEBUG_11H(priv, "abort channel switch on %d\n",
- le16_to_cpu(priv->switch_rxon.channel));
+ le16_to_cpu(priv->switch_channel));
iwl_legacy_chswitch_done(priv, false);
}
@@ -1404,9 +1404,6 @@
return rc;
}
- priv->switch_rxon.channel = cmd.channel;
- priv->switch_rxon.switch_in_progress = true;
-
return iwl_legacy_send_cmd_pdu(priv,
REPLY_CHANNEL_SWITCH, sizeof(cmd), &cmd);
}