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iwlagn: fix channel switch locking

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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 79d0732550
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>
This commit is contained in:
Stanislaw Gruszka 2011-06-02 18:17:15 +02:00 committed by John W. Linville
parent a99168eece
commit 6f213ff191
9 changed files with 28 additions and 119 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

74
drivers/net/wireless/iwlwifi/iwl-2000.c
View File

@ -177,79 +177,6 @@ static int iwl2000_hw_set_hw_params(struct iwl_priv *priv)
return 0;
}
static int iwl2030_hw_channel_switch(struct iwl_priv *priv,
struct ieee80211_channel_switch *ch_switch)
{
/*
* MULTI-FIXME
* See iwl_mac_channel_switch.
*/
struct iwl_rxon_context *ctx = &priv->contexts[IWL_RXON_CTX_BSS];
struct iwl6000_channel_switch_cmd cmd;
const struct iwl_channel_info *ch_info;
u32 switch_time_in_usec, ucode_switch_time;
u16 ch;
u32 tsf_low;
u8 switch_count;
u16 beacon_interval = le16_to_cpu(ctx->timing.beacon_interval);
struct ieee80211_vif *vif = ctx->vif;
struct iwl_host_cmd hcmd = {
.id = REPLY_CHANNEL_SWITCH,
.len = { sizeof(cmd), },
.flags = CMD_SYNC,
.data = { &cmd, },
};
cmd.band = priv->band == IEEE80211_BAND_2GHZ;
ch = ch_switch->channel->hw_value;
IWL_DEBUG_11H(priv, "channel switch from %u to %u\n",
ctx->active.channel, ch);
cmd.channel = cpu_to_le16(ch);
cmd.rxon_flags = ctx->staging.flags;
cmd.rxon_filter_flags = ctx->staging.filter_flags;
switch_count = ch_switch->count;
tsf_low = ch_switch->timestamp & 0x0ffffffff;
/*
* calculate the ucode channel switch time
* adding TSF as one of the factor for when to switch
*/
if ((priv->ucode_beacon_time > tsf_low) && beacon_interval) {
if (switch_count > ((priv->ucode_beacon_time - tsf_low) /
beacon_interval)) {
switch_count -= (priv->ucode_beacon_time -
tsf_low) / beacon_interval;
} else
switch_count = 0;
}
if (switch_count <= 1)
cmd.switch_time = cpu_to_le32(priv->ucode_beacon_time);
else {
switch_time_in_usec =
vif->bss_conf.beacon_int * switch_count * TIME_UNIT;
ucode_switch_time = iwl_usecs_to_beacons(priv,
switch_time_in_usec,
beacon_interval);
cmd.switch_time = iwl_add_beacon_time(priv,
priv->ucode_beacon_time,
ucode_switch_time,
beacon_interval);
}
IWL_DEBUG_11H(priv, "uCode time for the switch is 0x%x\n",
cmd.switch_time);
ch_info = iwl_get_channel_info(priv, priv->band, ch);
if (ch_info)
cmd.expect_beacon = is_channel_radar(ch_info);
else {
IWL_ERR(priv, "invalid channel switch from %u to %u\n",
ctx->active.channel, ch);
return -EFAULT;
}
priv->switch_rxon.channel = cmd.channel;
priv->switch_rxon.switch_in_progress = true;
return iwl_send_cmd_sync(priv, &hcmd);
}
static struct iwl_lib_ops iwl2000_lib = {
.set_hw_params = iwl2000_hw_set_hw_params,
.rx_handler_setup = iwlagn_rx_handler_setup,
@ -258,7 +185,6 @@ static struct iwl_lib_ops iwl2000_lib = {
.is_valid_rtc_data_addr = iwlagn_hw_valid_rtc_data_addr,
.send_tx_power = iwlagn_send_tx_power,
.update_chain_flags = iwl_update_chain_flags,
.set_channel_switch = iwl2030_hw_channel_switch,
.apm_ops = {
.init = iwl_apm_init,
.config = iwl2000_nic_config,

2
drivers/net/wireless/iwlwifi/iwl-5000.c
View File

@ -331,8 +331,6 @@ static int iwl5000_hw_channel_switch(struct iwl_priv *priv,
ctx->active.channel, ch);
return -EFAULT;
}
priv->switch_rxon.channel = cmd.channel;
priv->switch_rxon.switch_in_progress = true;
return iwl_send_cmd_sync(priv, &hcmd);
}

2
drivers/net/wireless/iwlwifi/iwl-6000.c
View File

@ -270,8 +270,6 @@ static int iwl6000_hw_channel_switch(struct iwl_priv *priv,
ctx->active.channel, ch);
return -EFAULT;
}
priv->switch_rxon.channel = cmd.channel;
priv->switch_rxon.switch_in_progress = true;
return iwl_send_cmd_sync(priv, &hcmd);
}

6
drivers/net/wireless/iwlwifi/iwl-agn-rxon.c
View File

@ -342,10 +342,10 @@ int iwlagn_commit_rxon(struct iwl_priv *priv, struct iwl_rxon_context *ctx)
* 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_chswitch_done(priv, false);
}

19
drivers/net/wireless/iwlwifi/iwl-agn.c
View File

@ -2843,16 +2843,13 @@ static void iwlagn_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_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;
@ -2901,15 +2898,19 @@ static void iwlagn_mac_channel_switch(struct ieee80211_hw *hw,
* at this point, staging_rxon has the
* configuration for channel switch
*/
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))
priv->switch_rxon.switch_in_progress = false;
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");
}

6
drivers/net/wireless/iwlwifi/iwl-core.c
View File

@ -843,12 +843,8 @@ void iwl_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);
}
}
#ifdef CONFIG_IWLWIFI_DEBUG

1
drivers/net/wireless/iwlwifi/iwl-core.h
View File

@ -560,6 +560,7 @@ void iwlcore_free_geos(struct iwl_priv *priv);
#define STATUS_POWER_PMI 16
#define STATUS_FW_ERROR 17
#define STATUS_DEVICE_ENABLED 18
#define STATUS_CHANNEL_SWITCH_PENDING 19
static inline int iwl_is_ready(struct iwl_priv *priv)

13
drivers/net/wireless/iwlwifi/iwl-dev.h
View File

@ -981,17 +981,6 @@ 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
@ -1287,7 +1276,7 @@ struct iwl_priv {
struct iwl_rxon_context contexts[NUM_IWL_RXON_CTX];
struct iwl_switch_rxon switch_rxon;
__le16 switch_channel;
struct {
u32 error_event_table;

24
drivers/net/wireless/iwlwifi/iwl-rx.c
View File

@ -250,19 +250,19 @@ static void iwl_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_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);
}
}