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linux/drivers/net/wireless/iwlwifi/iwl-power.c
Johannes Berg f0f74a0e65 iwlwifi: fix PS disable status race 
iwlwifi internally needs to keep track of whether PS
is enabled in the firmware or not. To do this, it keeps
a bit in the status flags, called STATUS_POWER_PMI.

The code to set this bit looks as follows:

static int iwl_set_power(struct iwl_priv *priv, void *cmd)
{
	return iwl_send_cmd_pdu_async(priv, POWER_TABLE_CMD,
				      sizeof(struct iwl_powertable_cmd),
				      cmd, NULL);
}

int iwl_power_update_mode(...)
{
	[...]
	if (final_mode != IWL_POWER_MODE_CAM)
		set_bit(STATUS_POWER_PMI, &priv->status);

	iwl_update_power_cmd(priv, &cmd, final_mode);
	cmd.keep_alive_beacons = 0;

	if (final_mode == IWL_POWER_INDEX_5)
		cmd.flags |= IWL_POWER_FAST_PD;

	ret = iwl_set_power(priv, &cmd);

	if (final_mode == IWL_POWER_MODE_CAM)
		clear_bit(STATUS_POWER_PMI, &priv->status);
	else
		set_bit(STATUS_POWER_PMI, &priv->status);

	if (priv->cfg->ops->lib->update_chain_flags && update_chains)
		priv->cfg->ops->lib->update_chain_flags(priv);
	[...]
}

Now, this bit really needs to track what the _firmware_
thinks, not what the driver thinks. Therefore, there is
a race condition here -- the driver sets the bit before
it knows that the async command sent to the card in the
iwl_set_power function has been processed. As a result,
the call to update_chain_flags() may think that the card
has been woken up (PMI bit cleared) while in reality it
hasn't processed the async POWER_TABLE_CMD yet.

This leads to bugs -- any commands the update_chain_flags
function sends can get stuck and subsequent commands also
fail.

The fix is almost trivial: since there's no reason to send
an async command here (in fact, there almost never should
be since many mac80211 callbacks can sleep) just make the
function wait for the card to process the command and then
return and clear the PMI bit.

Signed-off-by: Johannes Berg <johannes@sipsolutions.net>
Acked-by: Mohamed Abbas <mohamed.abbas@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2009-05-11 15:23:58 -04:00

445 lines
13 KiB
C
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/******************************************************************************
*
* Copyright(c) 2007 - 2009 Intel Corporation. All rights reserved.
*
* Portions of this file are derived from the ipw3945 project, as well
* as portions of the ieee80211 subsystem header files.
*
* This program is free software; you can redistribute it and/or modify it
* under the terms of version 2 of the GNU General Public License as
* published by the Free Software Foundation.
*
* This program is distributed in the hope that it will be useful, but WITHOUT
* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for
* more details.
*
* You should have received a copy of the GNU General Public License along with
* this program; if not, write to the Free Software Foundation, Inc.,
* 51 Franklin Street, Fifth Floor, Boston, MA 02110, USA
*
* The full GNU General Public License is included in this distribution in the
* file called LICENSE.
*
* Contact Information:
* Intel Linux Wireless <ilw@linux.intel.com>
* Intel Corporation, 5200 N.E. Elam Young Parkway, Hillsboro, OR 97124-6497
*****************************************************************************/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <net/mac80211.h>
#include "iwl-eeprom.h"
#include "iwl-dev.h"
#include "iwl-core.h"
#include "iwl-commands.h"
#include "iwl-debug.h"
#include "iwl-power.h"
/*
* Setting power level allow the card to go to sleep when not busy
* there are three factor that decide the power level to go to, they
* are list here with its priority
* 1- critical_power_setting this will be set according to card temperature.
* 2- system_power_setting this will be set by system PM manager.
* 3- user_power_setting this will be set by user either by writing to sys or
* mac80211
*
* if system_power_setting and user_power_setting is set to auto
* the power level will be decided according to association status and battery
* status.
*
*/
#define MSEC_TO_USEC 1024
#define IWL_POWER_RANGE_0_MAX (2)
#define IWL_POWER_RANGE_1_MAX (10)
#define IWL_POWER_ON_BATTERY IWL_POWER_INDEX_5
#define IWL_POWER_ON_AC_DISASSOC IWL_POWER_MODE_CAM
#define IWL_POWER_ON_AC_ASSOC IWL_POWER_MODE_CAM
#define IWL_CT_KILL_TEMPERATURE 110
#define IWL_MIN_POWER_TEMPERATURE 100
#define IWL_REDUCED_POWER_TEMPERATURE 95
/* default power management (not Tx power) table values */
/* for TIM 0-10 */
static struct iwl_power_vec_entry range_0[IWL_POWER_MAX] = {
{{NOSLP, SLP_TOUT(0), SLP_TOUT(0), SLP_VEC(0, 0, 0, 0, 0)}, 0},
{{SLP, SLP_TOUT(200), SLP_TOUT(500), SLP_VEC(1, 2, 2, 2, 0xFF)}, 0},
{{SLP, SLP_TOUT(200), SLP_TOUT(300), SLP_VEC(1, 2, 2, 2, 0xFF)}, 0},
{{SLP, SLP_TOUT(50), SLP_TOUT(100), SLP_VEC(2, 2, 2, 2, 0xFF)}, 0},
{{SLP, SLP_TOUT(50), SLP_TOUT(25), SLP_VEC(2, 2, 4, 4, 0xFF)}, 1},
{{SLP, SLP_TOUT(25), SLP_TOUT(25), SLP_VEC(2, 2, 4, 6, 0xFF)}, 2}
};
/* for TIM = 3-10 */
static struct iwl_power_vec_entry range_1[IWL_POWER_MAX] = {
{{NOSLP, SLP_TOUT(0), SLP_TOUT(0), SLP_VEC(0, 0, 0, 0, 0)}, 0},
{{SLP, SLP_TOUT(200), SLP_TOUT(500), SLP_VEC(1, 2, 3, 4, 4)}, 0},
{{SLP, SLP_TOUT(200), SLP_TOUT(300), SLP_VEC(1, 2, 3, 4, 7)}, 0},
{{SLP, SLP_TOUT(50), SLP_TOUT(100), SLP_VEC(2, 4, 6, 7, 9)}, 0},
{{SLP, SLP_TOUT(50), SLP_TOUT(25), SLP_VEC(2, 4, 6, 9, 10)}, 1},
{{SLP, SLP_TOUT(25), SLP_TOUT(25), SLP_VEC(2, 4, 7, 10, 10)}, 2}
};
/* for TIM > 11 */
static struct iwl_power_vec_entry range_2[IWL_POWER_MAX] = {
{{NOSLP, SLP_TOUT(0), SLP_TOUT(0), SLP_VEC(0, 0, 0, 0, 0)}, 0},
{{SLP, SLP_TOUT(200), SLP_TOUT(500), SLP_VEC(1, 2, 3, 4, 0xFF)}, 0},
{{SLP, SLP_TOUT(200), SLP_TOUT(300), SLP_VEC(2, 4, 6, 7, 0xFF)}, 0},
{{SLP, SLP_TOUT(50), SLP_TOUT(100), SLP_VEC(2, 7, 9, 9, 0xFF)}, 0},
{{SLP, SLP_TOUT(50), SLP_TOUT(25), SLP_VEC(2, 7, 9, 9, 0xFF)}, 0},
{{SLP, SLP_TOUT(25), SLP_TOUT(25), SLP_VEC(4, 7, 10, 10, 0xFF)}, 0}
};
/* set card power command */
static int iwl_set_power(struct iwl_priv *priv, void *cmd)
{
return iwl_send_cmd_pdu(priv, POWER_TABLE_CMD,
sizeof(struct iwl_powertable_cmd), cmd);
}
/* decide the right power level according to association status
* and battery status
*/
static u16 iwl_get_auto_power_mode(struct iwl_priv *priv)
{
u16 mode;
switch (priv->power_data.user_power_setting) {
case IWL_POWER_AUTO:
/* if running on battery */
if (priv->power_data.is_battery_active)
mode = IWL_POWER_ON_BATTERY;
else if (iwl_is_associated(priv))
mode = IWL_POWER_ON_AC_ASSOC;
else
mode = IWL_POWER_ON_AC_DISASSOC;
break;
default:
mode = priv->power_data.user_power_setting;
break;
}
return mode;
}
/* initialize to default */
static void iwl_power_init_handle(struct iwl_priv *priv)
{
struct iwl_power_mgr *pow_data;
int size = sizeof(struct iwl_power_vec_entry) * IWL_POWER_MAX;
struct iwl_powertable_cmd *cmd;
int i;
u16 lctl;
IWL_DEBUG_POWER(priv, "Initialize power \n");
pow_data = &priv->power_data;
memset(pow_data, 0, sizeof(*pow_data));
memcpy(&pow_data->pwr_range_0[0], &range_0[0], size);
memcpy(&pow_data->pwr_range_1[0], &range_1[0], size);
memcpy(&pow_data->pwr_range_2[0], &range_2[0], size);
lctl = iwl_pcie_link_ctl(priv);
IWL_DEBUG_POWER(priv, "adjust power command flags\n");
for (i = 0; i < IWL_POWER_MAX; i++) {
cmd = &pow_data->pwr_range_0[i].cmd;
if (lctl & PCI_CFG_LINK_CTRL_VAL_L0S_EN)
cmd->flags &= ~IWL_POWER_PCI_PM_MSK;
else
cmd->flags |= IWL_POWER_PCI_PM_MSK;
}
}
/* adjust power command according to DTIM period and power level*/
static int iwl_update_power_cmd(struct iwl_priv *priv,
struct iwl_powertable_cmd *cmd, u16 mode)
{
struct iwl_power_vec_entry *range;
struct iwl_power_mgr *pow_data;
int i;
u32 max_sleep = 0;
u8 period;
bool skip;
if (mode > IWL_POWER_INDEX_5) {
IWL_DEBUG_POWER(priv, "Error invalid power mode \n");
return -EINVAL;
}
pow_data = &priv->power_data;
if (pow_data->dtim_period <= IWL_POWER_RANGE_0_MAX)
range = &pow_data->pwr_range_0[0];
else if (pow_data->dtim_period <= IWL_POWER_RANGE_1_MAX)
range = &pow_data->pwr_range_1[0];
else
range = &pow_data->pwr_range_2[0];
period = pow_data->dtim_period;
memcpy(cmd, &range[mode].cmd, sizeof(struct iwl_powertable_cmd));
if (period == 0) {
period = 1;
skip = false;
} else {
skip = !!range[mode].no_dtim;
}
if (skip) {
__le32 slp_itrvl = cmd->sleep_interval[IWL_POWER_VEC_SIZE - 1];
max_sleep = le32_to_cpu(slp_itrvl);
if (max_sleep == 0xFF)
max_sleep = period * (skip + 1);
else if (max_sleep > period)
max_sleep = (le32_to_cpu(slp_itrvl) / period) * period;
cmd->flags |= IWL_POWER_SLEEP_OVER_DTIM_MSK;
} else {
max_sleep = period;
cmd->flags &= ~IWL_POWER_SLEEP_OVER_DTIM_MSK;
}
for (i = 0; i < IWL_POWER_VEC_SIZE; i++)
if (le32_to_cpu(cmd->sleep_interval[i]) > max_sleep)
cmd->sleep_interval[i] = cpu_to_le32(max_sleep);
IWL_DEBUG_POWER(priv, "Flags value = 0x%08X\n", cmd->flags);
IWL_DEBUG_POWER(priv, "Tx timeout = %u\n", le32_to_cpu(cmd->tx_data_timeout));
IWL_DEBUG_POWER(priv, "Rx timeout = %u\n", le32_to_cpu(cmd->rx_data_timeout));
IWL_DEBUG_POWER(priv, "Sleep interval vector = { %d , %d , %d , %d , %d }\n",
le32_to_cpu(cmd->sleep_interval[0]),
le32_to_cpu(cmd->sleep_interval[1]),
le32_to_cpu(cmd->sleep_interval[2]),
le32_to_cpu(cmd->sleep_interval[3]),
le32_to_cpu(cmd->sleep_interval[4]));
return 0;
}
/*
* compute the final power mode index
*/
int iwl_power_update_mode(struct iwl_priv *priv, bool force)
{
struct iwl_power_mgr *setting = &(priv->power_data);
int ret = 0;
u16 uninitialized_var(final_mode);
bool update_chains;
/* Don't update the RX chain when chain noise calibration is running */
update_chains = priv->chain_noise_data.state == IWL_CHAIN_NOISE_DONE ||
priv->chain_noise_data.state == IWL_CHAIN_NOISE_ALIVE;
/* If on battery, set to 3,
* if plugged into AC power, set to CAM ("continuously aware mode"),
* else user level */
switch (setting->system_power_setting) {
case IWL_POWER_SYS_AUTO:
final_mode = iwl_get_auto_power_mode(priv);
break;
case IWL_POWER_SYS_BATTERY:
final_mode = IWL_POWER_INDEX_3;
break;
case IWL_POWER_SYS_AC:
final_mode = IWL_POWER_MODE_CAM;
break;
default:
final_mode = IWL_POWER_INDEX_3;
WARN_ON(1);
}
if (setting->critical_power_setting > final_mode)
final_mode = setting->critical_power_setting;
/* driver only support CAM for non STA network */
if (priv->iw_mode != NL80211_IFTYPE_STATION)
final_mode = IWL_POWER_MODE_CAM;
if (iwl_is_ready_rf(priv) && !setting->power_disabled &&
((setting->power_mode != final_mode) || force)) {
struct iwl_powertable_cmd cmd;
if (final_mode != IWL_POWER_MODE_CAM)
set_bit(STATUS_POWER_PMI, &priv->status);
iwl_update_power_cmd(priv, &cmd, final_mode);
cmd.keep_alive_beacons = 0;
if (final_mode == IWL_POWER_INDEX_5)
cmd.flags |= IWL_POWER_FAST_PD;
ret = iwl_set_power(priv, &cmd);
if (final_mode == IWL_POWER_MODE_CAM)
clear_bit(STATUS_POWER_PMI, &priv->status);
else
set_bit(STATUS_POWER_PMI, &priv->status);
if (priv->cfg->ops->lib->update_chain_flags && update_chains)
priv->cfg->ops->lib->update_chain_flags(priv);
else
IWL_DEBUG_POWER(priv, "Cannot update the power, chain noise "
"calibration running: %d\n",
priv->chain_noise_data.state);
if (!ret)
setting->power_mode = final_mode;
}
return ret;
}
EXPORT_SYMBOL(iwl_power_update_mode);
/* Allow other iwl code to disable/enable power management active
* this will be useful for rate scale to disable PM during heavy
* Tx/Rx activities
*/
int iwl_power_disable_management(struct iwl_priv *priv, u32 ms)
{
u16 prev_mode;
int ret = 0;
if (priv->power_data.power_disabled)
return -EBUSY;
prev_mode = priv->power_data.user_power_setting;
priv->power_data.user_power_setting = IWL_POWER_MODE_CAM;
ret = iwl_power_update_mode(priv, 0);
priv->power_data.power_disabled = 1;
priv->power_data.user_power_setting = prev_mode;
cancel_delayed_work(&priv->set_power_save);
if (ms)
queue_delayed_work(priv->workqueue, &priv->set_power_save,
msecs_to_jiffies(ms));
return ret;
}
EXPORT_SYMBOL(iwl_power_disable_management);
/* Allow other iwl code to disable/enable power management active
* this will be useful for rate scale to disable PM during high
* volume activities
*/
int iwl_power_enable_management(struct iwl_priv *priv)
{
int ret = 0;
priv->power_data.power_disabled = 0;
ret = iwl_power_update_mode(priv, 0);
return ret;
}
EXPORT_SYMBOL(iwl_power_enable_management);
/* set user_power_setting */
int iwl_power_set_user_mode(struct iwl_priv *priv, u16 mode)
{
if (mode > IWL_POWER_MAX)
return -EINVAL;
priv->power_data.user_power_setting = mode;
return iwl_power_update_mode(priv, 0);
}
EXPORT_SYMBOL(iwl_power_set_user_mode);
/* set system_power_setting. This should be set by over all
* PM application.
*/
int iwl_power_set_system_mode(struct iwl_priv *priv, u16 mode)
{
if (mode < IWL_POWER_SYS_MAX)
priv->power_data.system_power_setting = mode;
else
return -EINVAL;
return iwl_power_update_mode(priv, 0);
}
EXPORT_SYMBOL(iwl_power_set_system_mode);
/* initialize to default */
void iwl_power_initialize(struct iwl_priv *priv)
{
iwl_power_init_handle(priv);
priv->power_data.user_power_setting = IWL_POWER_AUTO;
priv->power_data.system_power_setting = IWL_POWER_SYS_AUTO;
priv->power_data.power_disabled = 0;
priv->power_data.is_battery_active = 0;
priv->power_data.critical_power_setting = 0;
}
EXPORT_SYMBOL(iwl_power_initialize);
/* set critical_power_setting according to temperature value */
int iwl_power_temperature_change(struct iwl_priv *priv)
{
int ret = 0;
s32 temperature = KELVIN_TO_CELSIUS(priv->last_temperature);
u16 new_critical = priv->power_data.critical_power_setting;
if (temperature > IWL_CT_KILL_TEMPERATURE)
return 0;
else if (temperature > IWL_MIN_POWER_TEMPERATURE)
new_critical = IWL_POWER_INDEX_5;
else if (temperature > IWL_REDUCED_POWER_TEMPERATURE)
new_critical = IWL_POWER_INDEX_3;
else
new_critical = IWL_POWER_MODE_CAM;
if (new_critical != priv->power_data.critical_power_setting)
priv->power_data.critical_power_setting = new_critical;
if (priv->power_data.critical_power_setting >
priv->power_data.power_mode)
ret = iwl_power_update_mode(priv, 0);
return ret;
}
EXPORT_SYMBOL(iwl_power_temperature_change);
static void iwl_bg_set_power_save(struct work_struct *work)
{
struct iwl_priv *priv = container_of(work,
struct iwl_priv, set_power_save.work);
IWL_DEBUG_POWER(priv, "update power\n");
if (test_bit(STATUS_EXIT_PENDING, &priv->status))
return;
mutex_lock(&priv->mutex);
/* on starting association we disable power management
* until association, if association failed then this
* timer will expire and enable PM again.
*/
if (!iwl_is_associated(priv))
iwl_power_enable_management(priv);
mutex_unlock(&priv->mutex);
}
void iwl_setup_power_deferred_work(struct iwl_priv *priv)
{
INIT_DELAYED_WORK(&priv->set_power_save, iwl_bg_set_power_save);
}
EXPORT_SYMBOL(iwl_setup_power_deferred_work);
void iwl_power_cancel_timeout(struct iwl_priv *priv)
{
cancel_delayed_work(&priv->set_power_save);
}
EXPORT_SYMBOL(iwl_power_cancel_timeout);
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