linux/drivers/net/wireless/rt2x00/rt2x00ht.c
Helmut Schaa 01e946f22a rt2x00: Improve cooperation between rt2800pci and minstrel
In order to lower the impact of probe rates don't send a frame as AMPDU
if the rate control algorithm sets IEEE80211_TX_CTL_RATE_CTRL_PROBE.
Otherwise a whole aggregate would be send with a probe rate which might
lead to numerous retries.

Signed-off-by: Helmut Schaa <helmut.schaa@googlemail.com>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
Signed-off-by: John W. Linville <linville@tuxdriver.com>
2010-10-05 13:35:29 -04:00

145 lines
4.2 KiB
C

/*
Copyright (C) 2004 - 2009 Ivo van Doorn <IvDoorn@gmail.com>
<http://rt2x00.serialmonkey.com>
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation; either version 2 of the License, or
(at your option) any later version.
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.,
59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.
*/
/*
Module: rt2x00lib
Abstract: rt2x00 HT specific routines.
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include "rt2x00.h"
#include "rt2x00lib.h"
void rt2x00ht_create_tx_descriptor(struct queue_entry *entry,
struct txentry_desc *txdesc,
const struct rt2x00_rate *hwrate)
{
struct ieee80211_tx_info *tx_info = IEEE80211_SKB_CB(entry->skb);
struct ieee80211_tx_rate *txrate = &tx_info->control.rates[0];
struct ieee80211_hdr *hdr = (struct ieee80211_hdr *)entry->skb->data;
if (tx_info->control.sta)
txdesc->mpdu_density =
tx_info->control.sta->ht_cap.ampdu_density;
else
txdesc->mpdu_density = 0;
txdesc->ba_size = 7; /* FIXME: What value is needed? */
txdesc->stbc =
(tx_info->flags & IEEE80211_TX_CTL_STBC) >> IEEE80211_TX_CTL_STBC_SHIFT;
/*
* If IEEE80211_TX_RC_MCS is set txrate->idx just contains the
* mcs rate to be used
*/
if (txrate->flags & IEEE80211_TX_RC_MCS) {
txdesc->mcs = txrate->idx;
/*
* MIMO PS should be set to 1 for STA's using dynamic SM PS
* when using more then one tx stream (>MCS7).
*/
if (tx_info->control.sta && txdesc->mcs > 7 &&
((tx_info->control.sta->ht_cap.cap &
IEEE80211_HT_CAP_SM_PS) >>
IEEE80211_HT_CAP_SM_PS_SHIFT) ==
WLAN_HT_CAP_SM_PS_DYNAMIC)
__set_bit(ENTRY_TXD_HT_MIMO_PS, &txdesc->flags);
} else {
txdesc->mcs = rt2x00_get_rate_mcs(hwrate->mcs);
if (txrate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE)
txdesc->mcs |= 0x08;
}
/*
* This frame is eligible for an AMPDU, however, don't aggregate
* frames that are intended to probe a specific tx rate.
*/
if (tx_info->flags & IEEE80211_TX_CTL_AMPDU &&
!(tx_info->flags & IEEE80211_TX_CTL_RATE_CTRL_PROBE))
__set_bit(ENTRY_TXD_HT_AMPDU, &txdesc->flags);
/*
* Determine HT Mix/Greenfield rate mode
*/
if (txrate->flags & IEEE80211_TX_RC_MCS)
txdesc->rate_mode = RATE_MODE_HT_MIX;
if (txrate->flags & IEEE80211_TX_RC_GREEN_FIELD)
txdesc->rate_mode = RATE_MODE_HT_GREENFIELD;
/*
* Set 40Mhz mode if necessary (for legacy rates this will
* duplicate the frame to both channels).
*/
if (txrate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH ||
txrate->flags & IEEE80211_TX_RC_DUP_DATA)
__set_bit(ENTRY_TXD_HT_BW_40, &txdesc->flags);
if (txrate->flags & IEEE80211_TX_RC_SHORT_GI)
__set_bit(ENTRY_TXD_HT_SHORT_GI, &txdesc->flags);
/*
* Determine IFS values
* - Use TXOP_BACKOFF for management frames
* - Use TXOP_SIFS for fragment bursts
* - Use TXOP_HTTXOP for everything else
*
* Note: rt2800 devices won't use CTS protection (if used)
* for frames not transmitted with TXOP_HTTXOP
*/
if (ieee80211_is_mgmt(hdr->frame_control))
txdesc->txop = TXOP_BACKOFF;
else if (!(tx_info->flags & IEEE80211_TX_CTL_FIRST_FRAGMENT))
txdesc->txop = TXOP_SIFS;
else
txdesc->txop = TXOP_HTTXOP;
}
u16 rt2x00ht_center_channel(struct rt2x00_dev *rt2x00dev,
struct ieee80211_conf *conf)
{
struct hw_mode_spec *spec = &rt2x00dev->spec;
int center_channel;
u16 i;
/*
* Initialize center channel to current channel.
*/
center_channel = spec->channels[conf->channel->hw_value].channel;
/*
* Adjust center channel to HT40+ and HT40- operation.
*/
if (conf_is_ht40_plus(conf))
center_channel += 2;
else if (conf_is_ht40_minus(conf))
center_channel -= (center_channel == 14) ? 1 : 2;
for (i = 0; i < spec->num_channels; i++)
if (spec->channels[i].channel == center_channel)
return i;
WARN_ON(1);
return conf->channel->hw_value;
}