On Tue, Mar 8, 2011 at 11:10 PM, M. A. <jdiq123@xxxxxxxxxxxxxx> wrote:
> Hi all,
>
> My question is how can I modify Minstrel HT rate control to be able to
> override it (by a boolean or otherwise) to select an MCS or specific
> rate index from user space (such that once set it driver will only try
> sending at that rate until unset then driver will resort back to
> Minstrel RC).
I don't think we can fix the MCS rate index from user space, may be we
need a hack.
iw dev <devname> set bitrates [legacy-<2.4|5> <legacy rate in Mbps>*]
and this is only for legacy rates.
>
> I have been able to change other kernel parameters at runtime(echo
> /sys/kernel/debug/ieee80211/...) by passing them through (fops) to
> DebugFs. however I am unsure of what parameters to pass through in the
> case of MCS rate fixing and what modifications to the code are
> required to achieve this.
don't know and I am not sure whether this can be easily done.
>
>
> Also I have been told that these sections of code facilitate the
> masking of rates;
>
> =========================================================================
> include/net/cfg80211.h: cfg80211_bitrate_mask
> -------------------------------------------------------------------------------------------------------
> /*
> * cfg80211_bitrate_mask - masks for bitrate control
> */
> struct cfg80211_bitrate_mask {
> struct {
> u32 legacy;
> /* TODO: add support for masking MCS rates; e.g.: */
> /* u8 mcs[IEEE80211_HT_MCS_MASK_LEN]; */
> } control[IEEE80211_NUM_BANDS];
> };
> -------------------------------------------------------------------------------------------------------
> net/mac80211/cfg.c ieee80211_set_bitrate_mask
> -------------------------------------------------------------------------------------------------------
> static int ieee80211_set_bitrate_mask(struct wiphy *wiphy,
> struct net_device *dev,
> const u8 *addr,
> const struct cfg80211_bitrate_mask *mask)
> {
> struct ieee80211_sub_if_data *sdata = IEEE80211_DEV_TO_SUB_IF(dev);
> struct ieee80211_local *local = wdev_priv(dev->ieee80211_ptr);
> int i;
>
> /*
> * This _could_ be supported by providing a hook for
> * drivers for this function, but at this point it
> * doesn't seem worth bothering.
> */
> if (local->hw.flags & IEEE80211_HW_HAS_RATE_CONTROL)
> return -EOPNOTSUPP;
>
>
> for (i = 0; i < IEEE80211_NUM_BANDS; i++)
> sdata->rc_rateidx_mask[i] = mask->control[i].legacy;
>
> return 0;
> }
> -------------------------------------------------------------------------------------------------------
> net/wireless/nl80211.c: nl80211_set_tx_bitrate_mask
> -------------------------------------------------------------------------------------------------------
> static int nl80211_set_tx_bitrate_mask(struct sk_buff *skb,
> struct genl_info *info)
> {
> struct nlattr *tb[NL80211_TXRATE_MAX + 1];
> struct cfg80211_registered_device *rdev = info->user_ptr[0];
> struct cfg80211_bitrate_mask mask;
> int rem, i;
> struct net_device *dev = info->user_ptr[1];
> struct nlattr *tx_rates;
> struct ieee80211_supported_band *sband;
>
> if (info->attrs[NL80211_ATTR_TX_RATES] == NULL)
> return -EINVAL;
>
> if (!rdev->ops->set_bitrate_mask)
> return -EOPNOTSUPP;
>
> memset(&mask, 0, sizeof(mask));
> /* Default to all rates enabled */
> for (i = 0; i < IEEE80211_NUM_BANDS; i++) {
> sband = rdev->wiphy.bands[i];
> mask.control[i].legacy =
> sband ? (1 << sband->n_bitrates) - 1 : 0;
> }
>
> /*
> * The nested attribute uses enum nl80211_band as the index. This maps
> * directly to the enum ieee80211_band values used in cfg80211.
> */
> nla_for_each_nested(tx_rates, info->attrs[NL80211_ATTR_TX_RATES], rem)
> {
> enum ieee80211_band band = nla_type(tx_rates);
> if (band < 0 || band >= IEEE80211_NUM_BANDS)
> return -EINVAL;
> sband = rdev->wiphy.bands[band];
> if (sband == NULL)
> return -EINVAL;
> nla_parse(tb, NL80211_TXRATE_MAX, nla_data(tx_rates),
> nla_len(tx_rates), nl80211_txattr_policy);
> if (tb[NL80211_TXRATE_LEGACY]) {
> mask.control[band].legacy = rateset_to_mask(
> sband,
> nla_data(tb[NL80211_TXRATE_LEGACY]),
> nla_len(tb[NL80211_TXRATE_LEGACY]));
> if (mask.control[band].legacy == 0)
> return -EINVAL;
> }
> }
>
> return rdev->ops->set_bitrate_mask(&rdev->wiphy, dev, NULL, &mask);
> }
As you see everything is for legacy thing and for MCS it's a TODO section.
> ====================================================================================================================
>
>
> Any help is much appreciated!
>
> Thank you all very much
> _______________________________________________
> ath9k-devel mailing list
> ath9k-devel@xxxxxxxxxxxxxxx
> https://lists.ath9k.org/mailman/listinfo/ath9k-devel
>
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