iwlagn: fix channel switch locking
We use priv->mutex to avoid race conditions between iwl_chswitch_done()
and iwlagn_mac_channel_switch(), when marking channel switch in
progress. But iwl_chswitch_done() can be called in atomic context
from iwl_rx_csa() or with mutex already taken from iwlagn_commit_rxon().
These bugs were introduced by:
commit 79d07325502e73508f917475bc1617b60979dd94
Author: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Date: Thu May 6 08:54:11 2010 -0700
iwlwifi: support channel switch offload in driver
To fix remove mutex from iwl_chswitch_done() and use atomic bitops for
marking channel switch pending.
Also remove iwl2030_hw_channel_switch() since 2000 series adapters are
2.4GHz only devices.
Cc: stable@kernel.org # 2.6.36+
Signed-off-by: Stanislaw Gruszka <sgruszka@redhat.com>
Acked-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
diff --git a/drivers/net/wireless/iwlwifi/iwl-rx.c b/drivers/net/wireless/iwlwifi/iwl-rx.c
index 0053e9e..b774517 100644
--- a/drivers/net/wireless/iwlwifi/iwl-rx.c
+++ b/drivers/net/wireless/iwlwifi/iwl-rx.c
@@ -250,19 +250,19 @@
struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_BSS];
struct iwl_rxon_cmd *rxon = (void *)&ctx->active;
- if (priv->switch_rxon.switch_in_progress) {
- if (!le32_to_cpu(csa->status) &&
- (csa->channel == priv->switch_rxon.channel)) {
- rxon->channel = csa->channel;
- ctx->staging.channel = csa->channel;
- IWL_DEBUG_11H(priv, "CSA notif: channel %d\n",
+ if (!test_bit(STATUS_CHANNEL_SWITCH_PENDING, &priv->status))
+ return;
+
+ if (!le32_to_cpu(csa->status) && csa->channel == priv->switch_channel) {
+ rxon->channel = csa->channel;
+ ctx->staging.channel = csa->channel;
+ IWL_DEBUG_11H(priv, "CSA notif: channel %d\n",
le16_to_cpu(csa->channel));
- iwl_chswitch_done(priv, true);
- } else {
- IWL_ERR(priv, "CSA notif (fail) : channel %d\n",
- le16_to_cpu(csa->channel));
- iwl_chswitch_done(priv, false);
- }
+ iwl_chswitch_done(priv, true);
+ } else {
+ IWL_ERR(priv, "CSA notif (fail) : channel %d\n",
+ le16_to_cpu(csa->channel));
+ iwl_chswitch_done(priv, false);
}
}