From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from mail-yw0-f46.google.com ([209.85.213.46]:53006 "EHLO mail-yw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751638Ab1EaRGv convert rfc822-to-8bit (ORCPT ); Tue, 31 May 2011 13:06:51 -0400 Received: by ywe9 with SMTP id 9so1881492ywe.19 for ; Tue, 31 May 2011 10:06:50 -0700 (PDT) MIME-Version: 1.0 In-Reply-To: References: Date: Tue, 31 May 2011 18:06:50 +0100 Message-ID: (sfid-20110531_190655_131683_B1BBE0D0) Subject: Re: [ath9k-devel] Override Minstrel HT RC to set an MCS bitrate (mask) From: "M. A." To: ath9k-devel@lists.ath9k.org, linux-wireless@vger.kernel.org Content-Type: text/plain; charset=ISO-8859-1 Sender: linux-wireless-owner@vger.kernel.org List-ID: Hi all, I would be grateful if anyone can advise on setting/masking a fixed MCS HT rate (ath9k) at runtime, as I am only able to mask legacy rates.. If this is not yet implemented, can anyone please advise on how to implement this as I am in urgent need of this functionality. Thank you all in advance! > On Tue, Mar 15, 2011 at 5:02 AM, Mohammed Shafi wrote: >> On Tue, Mar 8, 2011 at 11:10 PM, M. A. 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 set bitrates [legacy-<2.4|5> *] >> 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@lists.ath9k.org >>> https://lists.ath9k.org/mailman/listinfo/ath9k-devel >>> >> >