iwlwifi: eliminate the possible 1/2 dBm tx power loss in 6x00 & 6x50 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>
This commit is contained in:
Wey-Yi Guy
2009-11-13 11:56:30 -08:00
committed by John W. Linville
parent 4d6ccbf57f
commit ae16fc3c31
3 changed files with 52 additions and 14 deletions

View File

@@ -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;