Re: [05/88] carl9170: fix frame drop and WARN due to minstrel_ht change

From: Luis Henriques
Date: Tue Aug 13 2013 - 13:15:39 EST

Steven Rostedt <rostedt@xxxxxxxxxxx> writes:

> 3.6.11.7-rc1 stable review patch.
> If anyone has any objections, please let me know.

Not exactly an objection, but the commit text refers to:

a0497f9 mac80211/minstrel_ht: add support for using CCK rates

which doesn't seem to exist in 3.6 kernel. I wonder if this commit is
actually needed.

Cheers,
--
Luis


>
> ------------------
>
> From: Christian Lamparter <chunkeey@xxxxxxxxxxxxxx>
>
> [ Upstream commit 5f34608fa2acbfef5a06d0072a978c9943c28a2d ]
>
> With "mac80211/minstrel_ht: add support for using CCK rates"
> minstrel_ht selects legacy CCK rates as viable rates for
> outgoing frames which might be sent as part of an A-MPDU
> [IEEE80211_TX_CTL_AMPDU is set].
>
> This behavior triggered the following WARN_ON in the driver:
>> WARNING: at carl9170/tx.c:995 carl9170_op_tx+0x1dd/0x6fd
> The driver assumed that the rate control algorithm made a
> mistake and dropped the frame.
>
> This patch removes the noisy warning altogether and allows
> said A-MPDU frames with CCK sample and/or fallback rates to
> be transmitted seamlessly.
>
> Signed-off-by: Christian Lamparter <chunkeey@xxxxxxxxxxxxxx>
> Signed-off-by: John W. Linville <linville@xxxxxxxxxxxxx>
> Signed-off-by: Steven Rostedt <rostedt@xxxxxxxxxxx>
> ---
> drivers/net/wireless/ath/carl9170/tx.c | 69 +++++++++++++-------------------
> 1 file changed, 28 insertions(+), 41 deletions(-)
>
> diff --git a/drivers/net/wireless/ath/carl9170/tx.c b/drivers/net/wireless/ath/carl9170/tx.c
> index 6a86814..745e9dd 100644
> --- a/drivers/net/wireless/ath/carl9170/tx.c
> +++ b/drivers/net/wireless/ath/carl9170/tx.c
> @@ -387,8 +387,7 @@ static void carl9170_tx_status_process_ampdu(struct ar9170 *ar,
> u8 tid;
>
> if (!(txinfo->flags & IEEE80211_TX_CTL_AMPDU) ||
> - txinfo->flags & IEEE80211_TX_CTL_INJECTED ||
> - (!(super->f.mac_control & cpu_to_le16(AR9170_TX_MAC_AGGR))))
> + txinfo->flags & IEEE80211_TX_CTL_INJECTED)
> return;
>
> rcu_read_lock();
> @@ -982,30 +981,6 @@ static int carl9170_tx_prepare(struct ar9170 *ar, struct sk_buff *skb)
>
> SET_VAL(CARL9170_TX_SUPER_AMPDU_FACTOR,
> txc->s.ampdu_settings, factor);
> -
> - for (i = 0; i < CARL9170_TX_MAX_RATES; i++) {
> - txrate = &info->control.rates[i];
> - if (txrate->idx >= 0) {
> - txc->s.ri[i] =
> - CARL9170_TX_SUPER_RI_AMPDU;
> -
> - if (WARN_ON(!(txrate->flags &
> - IEEE80211_TX_RC_MCS))) {
> - /*
> - * Not sure if it's even possible
> - * to aggregate non-ht rates with
> - * this HW.
> - */
> - goto err_out;
> - }
> - continue;
> - }
> -
> - txrate->idx = 0;
> - txrate->count = ar->hw->max_rate_tries;
> - }
> -
> - mac_tmp |= cpu_to_le16(AR9170_TX_MAC_AGGR);
> }
>
> /*
> @@ -1013,11 +988,31 @@ static int carl9170_tx_prepare(struct ar9170 *ar, struct sk_buff *skb)
> * taken from mac_control. For all fallback rate, the firmware
> * updates the mac_control flags from the rate info field.
> */
> - for (i = 1; i < CARL9170_TX_MAX_RATES; i++) {
> + for (i = 0; i < CARL9170_TX_MAX_RATES; i++) {
> + __le32 phy_set;
> txrate = &info->control.rates[i];
> if (txrate->idx < 0)
> break;
>
> + phy_set = carl9170_tx_physet(ar, info, txrate);
> + if (i == 0) {
> + /* first rate - part of the hw's frame header */
> + txc->f.phy_control = phy_set;
> +
> + if (ampdu && txrate->flags & IEEE80211_TX_RC_MCS)
> + mac_tmp |= cpu_to_le16(AR9170_TX_MAC_AGGR);
> + if (carl9170_tx_rts_check(ar, txrate, ampdu, no_ack))
> + mac_tmp |= cpu_to_le16(AR9170_TX_MAC_PROT_RTS);
> + else if (carl9170_tx_cts_check(ar, txrate))
> + mac_tmp |= cpu_to_le16(AR9170_TX_MAC_PROT_CTS);
> +
> + } else {
> + /* fallback rates are stored in the firmware's
> + * retry rate set array.
> + */
> + txc->s.rr[i - 1] = phy_set;
> + }
> +
> SET_VAL(CARL9170_TX_SUPER_RI_TRIES, txc->s.ri[i],
> txrate->count);
>
> @@ -1028,21 +1023,13 @@ static int carl9170_tx_prepare(struct ar9170 *ar, struct sk_buff *skb)
> txc->s.ri[i] |= (AR9170_TX_MAC_PROT_CTS <<
> CARL9170_TX_SUPER_RI_ERP_PROT_S);
>
> - txc->s.rr[i - 1] = carl9170_tx_physet(ar, info, txrate);
> + if (ampdu && (txrate->flags & IEEE80211_TX_RC_MCS))
> + txc->s.ri[i] |= CARL9170_TX_SUPER_RI_AMPDU;
> }
>
> - txrate = &info->control.rates[0];
> - SET_VAL(CARL9170_TX_SUPER_RI_TRIES, txc->s.ri[0], txrate->count);
> -
> - if (carl9170_tx_rts_check(ar, txrate, ampdu, no_ack))
> - mac_tmp |= cpu_to_le16(AR9170_TX_MAC_PROT_RTS);
> - else if (carl9170_tx_cts_check(ar, txrate))
> - mac_tmp |= cpu_to_le16(AR9170_TX_MAC_PROT_CTS);
> -
> txc->s.len = cpu_to_le16(skb->len);
> txc->f.length = cpu_to_le16(len + FCS_LEN);
> txc->f.mac_control = mac_tmp;
> - txc->f.phy_control = carl9170_tx_physet(ar, info, txrate);
>
> arinfo = (void *)info->rate_driver_data;
> arinfo->timeout = jiffies;
> @@ -1382,9 +1369,9 @@ static void carl9170_tx(struct ar9170 *ar)
> }
>
> static bool carl9170_tx_ampdu_queue(struct ar9170 *ar,
> - struct ieee80211_sta *sta, struct sk_buff *skb)
> + struct ieee80211_sta *sta, struct sk_buff *skb,
> + struct ieee80211_tx_info *txinfo)
> {
> - struct _carl9170_tx_superframe *super = (void *) skb->data;
> struct carl9170_sta_info *sta_info;
> struct carl9170_sta_tid *agg;
> struct sk_buff *iter;
> @@ -1451,7 +1438,7 @@ err_unlock:
>
> err_unlock_rcu:
> rcu_read_unlock();
> - super->f.mac_control &= ~cpu_to_le16(AR9170_TX_MAC_AGGR);
> + txinfo->flags &= ~IEEE80211_TX_CTL_AMPDU;
> carl9170_tx_status(ar, skb, false);
> ar->tx_dropped++;
> return false;
> @@ -1485,7 +1472,7 @@ void carl9170_op_tx(struct ieee80211_hw *hw, struct sk_buff *skb)
> }
>
> if (info->flags & IEEE80211_TX_CTL_AMPDU) {
> - run = carl9170_tx_ampdu_queue(ar, sta, skb);
> + run = carl9170_tx_ampdu_queue(ar, sta, skb, info);
> if (run)
> carl9170_tx_ampdu(ar);
--
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