linux/drivers/net/wireless/rt2x00/rt2x00ht.c
Gertjan van Wingerde 06443e46c6 rt2x00: Fix HT40 operation in rt2800.
Closer inspection of the legacy Ralink driver reveals that in case of HT40+
or HT40- we must adjust the frequency settings that we program to the device.
Implement the same adjustment in the rt2x00 code.

With this HT40 seems to work for all devices supported by rt2800pci and
rt2800usb.

Signed-off-by: Gertjan van Wingerde <gwingerde@gmail.com>
Signed-off-by: Ivo van Doorn <IvDoorn@gmail.com>
2010-06-03 10:52:08 +02:00

115 lines
3.3 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 = 0; /* FIXME: What value is needed? */
txdesc->mcs = rt2x00_get_rate_mcs(hwrate->mcs);
if (txrate->flags & IEEE80211_TX_RC_USE_SHORT_PREAMBLE)
txdesc->mcs |= 0x08;
/*
* Convert flags
*/
if (tx_info->flags & IEEE80211_TX_CTL_AMPDU)
__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;
if (txrate->flags & IEEE80211_TX_RC_40_MHZ_WIDTH)
__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;
}