Skip to content

Commit

Permalink
iwlwifi: eliminate the possible 1/2 dBm tx power loss in 6x00 & 6x50 …
Browse files Browse the repository at this point in the history 
…series

In both 6x00 and 6x50 series, the enhanced/extended tx power table in
EEPROM is used to set the max. tx power limit.
This new tx power table is in 1/2 dBm format, which creates an issue of
possibility of 1/2 dBm loss when driver set the tx power limit; because
of driver keep track and report the tx power in dBm format.

In order to prevent the 1/2 dBm loss, keep track of the true max tx
power in 1/2 dBm format in driver; do the comparison and adjust the tx
power if needed when send tx power command to uCode.

Signed-off-by: Wey-Yi Guy <wey-yi.w.guy@intel.com>
Signed-off-by: Reinette Chatre <reinette.chatre@intel.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
  • Loading branch information
Wey-Yi Guy authored and John W. Linville committed Nov 18, 2009
1 parent 4d6ccbf commit ae16fc3
Show file tree
Hide file tree
Showing 3 changed files with 52 additions and 14 deletions.
16 changes: 16 additions & 0 deletions drivers/net/wireless/iwlwifi/iwl-5000.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1250,6 +1250,22 @@ int iwl5000_send_tx_power(struct iwl_priv *priv)

/* half dBm need to multiply */
tx_power_cmd.global_lmt = (s8)(2 * priv->tx_power_user_lmt);

if (priv->tx_power_lmt_in_half_dbm &&
priv->tx_power_lmt_in_half_dbm < tx_power_cmd.global_lmt) {
/*
* For the newer devices which using enhanced/extend tx power
* table in EEPROM, the format is in half dBm. driver need to
* convert to dBm format before report to mac80211.
* By doing so, there is a possibility of 1/2 dBm resolution
* lost. driver will perform "round-up" operation before
* reporting, but it will cause 1/2 dBm tx power over the
* regulatory limit. Perform the checking here, if the
* "tx_power_user_lmt" is higher than EEPROM value (in
* half-dBm format), lower the tx power based on EEPROM
*/
tx_power_cmd.global_lmt = priv->tx_power_lmt_in_half_dbm;
}
tx_power_cmd.flags = IWL50_TX_POWER_NO_CLOSED;
tx_power_cmd.srv_chan_lmt = IWL50_TX_POWER_AUTO;

Expand Down
1 change: 1 addition & 0 deletions drivers/net/wireless/iwlwifi/iwl-dev.h
View file
Original file line number Diff line number Diff line change
Expand Up @@ -1247,6 +1247,7 @@ struct iwl_priv {
/* TX Power */
s8 tx_power_user_lmt;
s8 tx_power_device_lmt;
s8 tx_power_lmt_in_half_dbm; /* max tx power in half-dBm format */


#ifdef CONFIG_IWLWIFI_DEBUG
Expand Down
49 changes: 35 additions & 14 deletions drivers/net/wireless/iwlwifi/iwl-eeprom.c
View file
Original file line number Diff line number Diff line change
Expand Up @@ -762,7 +762,8 @@ static int iwl_mod_ht40_chan_info(struct iwl_priv *priv,
* find the highest tx power from all chains for the channel
*/
static s8 iwl_get_max_txpower_avg(struct iwl_priv *priv,
struct iwl_eeprom_enhanced_txpwr *enhanced_txpower, int element)
struct iwl_eeprom_enhanced_txpwr *enhanced_txpower,
int element, s8 *max_txpower_in_half_dbm)
{
s8 max_txpower_avg = 0; /* (dBm) */

Expand Down Expand Up @@ -794,10 +795,14 @@ static s8 iwl_get_max_txpower_avg(struct iwl_priv *priv,
(enhanced_txpower[element].mimo3_max > max_txpower_avg))
max_txpower_avg = enhanced_txpower[element].mimo3_max;

/* max. tx power in EEPROM is in 1/2 dBm format
* convert from 1/2 dBm to dBm
/*
* max. tx power in EEPROM is in 1/2 dBm format
* convert from 1/2 dBm to dBm (round-up convert)
* but we also do not want to loss 1/2 dBm resolution which
* will impact performance
*/
return max_txpower_avg >> 1;
*max_txpower_in_half_dbm = max_txpower_avg;
return (max_txpower_avg & 0x01) + (max_txpower_avg >> 1);
}

/**
Expand All @@ -806,7 +811,7 @@ static s8 iwl_get_max_txpower_avg(struct iwl_priv *priv,
*/
static s8 iwl_update_common_txpower(struct iwl_priv *priv,
struct iwl_eeprom_enhanced_txpwr *enhanced_txpower,
int section, int element)
int section, int element, s8 *max_txpower_in_half_dbm)
{
struct iwl_channel_info *ch_info;
int ch;
Expand All @@ -820,20 +825,22 @@ static s8 iwl_update_common_txpower(struct iwl_priv *priv,
if (element == EEPROM_TXPOWER_COMMON_HT40_INDEX)
is_ht40 = true;
max_txpower_avg =
iwl_get_max_txpower_avg(priv, enhanced_txpower, element);
iwl_get_max_txpower_avg(priv, enhanced_txpower,
element, max_txpower_in_half_dbm);

ch_info = priv->channel_info;

for (ch = 0; ch < priv->channel_count; ch++) {
/* find matching band and update tx power if needed */
if ((ch_info->band == enhinfo[section].band) &&
(ch_info->max_power_avg < max_txpower_avg) && (!is_ht40)) {
(ch_info->max_power_avg < max_txpower_avg) &&
(!is_ht40)) {
/* Update regulatory-based run-time data */
ch_info->max_power_avg = ch_info->curr_txpow =
max_txpower_avg;
max_txpower_avg;
ch_info->scan_power = max_txpower_avg;
}
if ((ch_info->band == enhinfo[section].band) && is_ht40 &&
ch_info->ht40_max_power_avg &&
(ch_info->ht40_max_power_avg < max_txpower_avg)) {
/* Update regulatory-based run-time data */
ch_info->ht40_max_power_avg = max_txpower_avg;
Expand All @@ -849,7 +856,7 @@ static s8 iwl_update_common_txpower(struct iwl_priv *priv,
*/
static s8 iwl_update_channel_txpower(struct iwl_priv *priv,
struct iwl_eeprom_enhanced_txpwr *enhanced_txpower,
int section, int element)
int section, int element, s8 *max_txpower_in_half_dbm)
{
struct iwl_channel_info *ch_info;
int ch;
Expand All @@ -858,7 +865,8 @@ static s8 iwl_update_channel_txpower(struct iwl_priv *priv,

channel = enhinfo[section].iwl_eeprom_section_channel[element];
max_txpower_avg =
iwl_get_max_txpower_avg(priv, enhanced_txpower, element);
iwl_get_max_txpower_avg(priv, enhanced_txpower,
element, max_txpower_in_half_dbm);

ch_info = priv->channel_info;
for (ch = 0; ch < priv->channel_count; ch++) {
Expand All @@ -872,7 +880,6 @@ static s8 iwl_update_channel_txpower(struct iwl_priv *priv,
ch_info->scan_power = max_txpower_avg;
}
if ((enhinfo[section].is_ht40) &&
(ch_info->ht40_max_power_avg) &&
(ch_info->ht40_max_power_avg < max_txpower_avg)) {
/* Update regulatory-based run-time data */
ch_info->ht40_max_power_avg = max_txpower_avg;
Expand All @@ -894,6 +901,7 @@ void iwlcore_eeprom_enhanced_txpower(struct iwl_priv *priv)
struct iwl_eeprom_enhanced_txpwr *enhanced_txpower;
u32 offset;
s8 max_txpower_avg; /* (dBm) */
s8 max_txpower_in_half_dbm; /* (half-dBm) */

/* Loop through all the sections
* adjust bands and channel's max tx power
Expand All @@ -920,16 +928,29 @@ void iwlcore_eeprom_enhanced_txpower(struct iwl_priv *priv)
if (enhinfo[section].is_common)
max_txpower_avg =
iwl_update_common_txpower(priv,
enhanced_txpower, section, element);
enhanced_txpower, section,
element,
&max_txpower_in_half_dbm);
else
max_txpower_avg =
iwl_update_channel_txpower(priv,
enhanced_txpower, section, element);
enhanced_txpower, section,
element,
&max_txpower_in_half_dbm);

/* Update the tx_power_user_lmt to the highest power
* supported by any channel */
if (max_txpower_avg > priv->tx_power_user_lmt)
priv->tx_power_user_lmt = max_txpower_avg;

/*
* Update the tx_power_lmt_in_half_dbm to
* the highest power supported by any channel
*/
if (max_txpower_in_half_dbm >
priv->tx_power_lmt_in_half_dbm)
priv->tx_power_lmt_in_half_dbm =
max_txpower_in_half_dbm;
}
}
}
Expand Down

0 comments on commit ae16fc3

Please sign in to comment.