From: Stanislaw Gruszka Date: Wed, 8 Jun 2011 13:26:31 +0000 (+0200) Subject: iwlegacy: fix channel switch locking X-Git-Url: http://git.lede-project.org./?a=commitdiff_plain;h=51e65257142a87fe46a1ce5c35c86c5baf012614;p=openwrt%2Fstaging%2Fblogic.git 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 Signed-off-by: John W. Linville --- diff --git a/drivers/net/wireless/iwlegacy/iwl-4965.c b/drivers/net/wireless/iwlegacy/iwl-4965.c index e1b89220c186..facc94e74b07 100644 --- a/drivers/net/wireless/iwlegacy/iwl-4965.c +++ b/drivers/net/wireless/iwlegacy/iwl-4965.c @@ -1218,10 +1218,10 @@ static int iwl4965_commit_rxon(struct iwl_priv *priv, struct iwl_rxon_context *c * 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 @@ static int iwl4965_hw_channel_switch(struct iwl_priv *priv, 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); } diff --git a/drivers/net/wireless/iwlegacy/iwl-core.c b/drivers/net/wireless/iwlegacy/iwl-core.c index 42df8321dae8..3be76bd5499a 100644 --- a/drivers/net/wireless/iwlegacy/iwl-core.c +++ b/drivers/net/wireless/iwlegacy/iwl-core.c @@ -859,12 +859,8 @@ void iwl_legacy_chswitch_done(struct iwl_priv *priv, bool is_success) if (test_bit(STATUS_EXIT_PENDING, &priv->status)) return; - if (priv->switch_rxon.switch_in_progress) { + if (test_and_clear_bit(STATUS_CHANNEL_SWITCH_PENDING, &priv->status)) ieee80211_chswitch_done(ctx->vif, is_success); - mutex_lock(&priv->mutex); - priv->switch_rxon.switch_in_progress = false; - mutex_unlock(&priv->mutex); - } } EXPORT_SYMBOL(iwl_legacy_chswitch_done); @@ -876,19 +872,19 @@ void iwl_legacy_rx_csa(struct iwl_priv *priv, struct iwl_rx_mem_buffer *rxb) struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_BSS]; struct iwl_legacy_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", - le16_to_cpu(csa->channel)); - iwl_legacy_chswitch_done(priv, true); - } else { - IWL_ERR(priv, "CSA notif (fail) : 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_legacy_chswitch_done(priv, false); - } + iwl_legacy_chswitch_done(priv, true); + } else { + IWL_ERR(priv, "CSA notif (fail) : channel %d\n", + le16_to_cpu(csa->channel)); + iwl_legacy_chswitch_done(priv, false); } } EXPORT_SYMBOL(iwl_legacy_rx_csa); diff --git a/drivers/net/wireless/iwlegacy/iwl-core.h b/drivers/net/wireless/iwlegacy/iwl-core.h index bc66c604106c..c5fbda0760de 100644 --- a/drivers/net/wireless/iwlegacy/iwl-core.h +++ b/drivers/net/wireless/iwlegacy/iwl-core.h @@ -560,7 +560,7 @@ void iwl_legacy_free_geos(struct iwl_priv *priv); #define STATUS_SCAN_HW 15 #define STATUS_POWER_PMI 16 #define STATUS_FW_ERROR 17 - +#define STATUS_CHANNEL_SWITCH_PENDING 18 static inline int iwl_legacy_is_ready(struct iwl_priv *priv) { diff --git a/drivers/net/wireless/iwlegacy/iwl-dev.h b/drivers/net/wireless/iwlegacy/iwl-dev.h index be0106c6a2da..ea30122669ee 100644 --- a/drivers/net/wireless/iwlegacy/iwl-dev.h +++ b/drivers/net/wireless/iwlegacy/iwl-dev.h @@ -854,17 +854,6 @@ struct traffic_stats { #endif }; -/* - * iwl_switch_rxon: "channel switch" structure - * - * @ switch_in_progress: channel switch in progress - * @ channel: new channel - */ -struct iwl_switch_rxon { - bool switch_in_progress; - __le16 channel; -}; - /* * schedule the timer to wake up every UCODE_TRACE_PERIOD milliseconds * to perform continuous uCode event logging operation if enabled @@ -1115,7 +1104,7 @@ struct iwl_priv { struct iwl_rxon_context contexts[NUM_IWL_RXON_CTX]; - struct iwl_switch_rxon switch_rxon; + __le16 switch_channel; /* 1st responses from initialize and runtime uCode images. * _4965's initialize alive response contains some calibration data. */ diff --git a/drivers/net/wireless/iwlegacy/iwl4965-base.c b/drivers/net/wireless/iwlegacy/iwl4965-base.c index af2ae22fcfd3..7157ba529680 100644 --- a/drivers/net/wireless/iwlegacy/iwl4965-base.c +++ b/drivers/net/wireless/iwlegacy/iwl4965-base.c @@ -2861,16 +2861,13 @@ void iwl4965_mac_channel_switch(struct ieee80211_hw *hw, goto out; if (test_bit(STATUS_EXIT_PENDING, &priv->status) || - test_bit(STATUS_SCANNING, &priv->status)) + test_bit(STATUS_SCANNING, &priv->status) || + test_bit(STATUS_CHANNEL_SWITCH_PENDING, &priv->status)) goto out; if (!iwl_legacy_is_associated_ctx(ctx)) goto out; - /* channel switch in progress */ - if (priv->switch_rxon.switch_in_progress == true) - goto out; - if (priv->cfg->ops->lib->set_channel_switch) { ch = channel->hw_value; @@ -2919,15 +2916,18 @@ void iwl4965_mac_channel_switch(struct ieee80211_hw *hw, * at this point, staging_rxon has the * configuration for channel switch */ - if (priv->cfg->ops->lib->set_channel_switch(priv, - ch_switch)) - priv->switch_rxon.switch_in_progress = false; + set_bit(STATUS_CHANNEL_SWITCH_PENDING, &priv->status); + priv->switch_channel = cpu_to_le16(ch); + if (priv->cfg->ops->lib->set_channel_switch(priv, ch_switch)) { + clear_bit(STATUS_CHANNEL_SWITCH_PENDING, + &priv->status); + priv->switch_channel = 0; + ieee80211_chswitch_done(ctx->vif, false); + } } } out: mutex_unlock(&priv->mutex); - if (!priv->switch_rxon.switch_in_progress) - ieee80211_chswitch_done(ctx->vif, false); IWL_DEBUG_MAC80211(priv, "leave\n"); }