2010/1/21 Bob Copeland <me@xxxxxxxxxxxxxxx>:
> The beacon sent gating doesn't seem to work with any combination
> of flags. Thus, buffered frames tend to stay buffered forever,
> using up tx descriptors.
>
> Instead, use the DBA gating and hold transmission of the buffered
> frames until 80% of the beacon interval has elapsed using the ready
> time. This fixes the following error in AP mode:
>
> ath5k phy0: no further txbuf available, dropping packet
>
> Add a comment to acknowledge that this isn't the best solution.
>
> Signed-off-by: Bob Copeland <me@xxxxxxxxxxxxxxx>
> ---
> drivers/net/wireless/ath/ath5k/ath5k.h | 2 +-
> drivers/net/wireless/ath/ath5k/base.c | 22 +++++++++++++++++++---
> drivers/net/wireless/ath/ath5k/qcu.c | 5 +++--
> 3 files changed, 23 insertions(+), 6 deletions(-)
>
> diff --git a/drivers/net/wireless/ath/ath5k/ath5k.h b/drivers/net/wireless/ath/ath5k/ath5k.h
> index 66bcb50..ad4d446 100644
> --- a/drivers/net/wireless/ath/ath5k/ath5k.h
> +++ b/drivers/net/wireless/ath/ath5k/ath5k.h
> @@ -535,7 +535,7 @@ struct ath5k_txq_info {
> u32 tqi_cbr_period; /* Constant bit rate period */
> u32 tqi_cbr_overflow_limit;
> u32 tqi_burst_time;
> - u32 tqi_ready_time; /* Not used */
> + u32 tqi_ready_time; /* Time queue waits after an event */
> };
>
> /*
> diff --git a/drivers/net/wireless/ath/ath5k/base.c b/drivers/net/wireless/ath/ath5k/base.c
> index b501537..535a6af 100644
> --- a/drivers/net/wireless/ath/ath5k/base.c
> +++ b/drivers/net/wireless/ath/ath5k/base.c
> @@ -1516,7 +1516,8 @@ ath5k_beaconq_config(struct ath5k_softc *sc)
>
> ret = ath5k_hw_get_tx_queueprops(ah, sc->bhalq, &qi);
> if (ret)
> - return ret;
> + goto err;
> +
> if (sc->opmode == NL80211_IFTYPE_AP ||
> sc->opmode == NL80211_IFTYPE_MESH_POINT) {
> /*
> @@ -1543,10 +1544,25 @@ ath5k_beaconq_config(struct ath5k_softc *sc)
> if (ret) {
> ATH5K_ERR(sc, "%s: unable to update parameters for beacon "
> "hardware queue!\n", __func__);
> - return ret;
> + goto err;
> }
> + ret = ath5k_hw_reset_tx_queue(ah, sc->bhalq); /* push to h/w */
> + if (ret)
> + goto err;
>
> - return ath5k_hw_reset_tx_queue(ah, sc->bhalq); /* push to h/w */;
> + /* reconfigure cabq with ready time to 80% of beacon_interval */
> + ret = ath5k_hw_get_tx_queueprops(ah, AR5K_TX_QUEUE_ID_CAB, &qi);
> + if (ret)
> + goto err;
> +
> + qi.tqi_ready_time = (sc->bintval * 80) / 100;
> + ret = ath5k_hw_set_tx_queueprops(ah, AR5K_TX_QUEUE_ID_CAB, &qi);
> + if (ret)
> + goto err;
> +
> + ret = ath5k_hw_reset_tx_queue(ah, AR5K_TX_QUEUE_ID_CAB);
> +err:
> + return ret;
> }
>
> static void
> diff --git a/drivers/net/wireless/ath/ath5k/qcu.c b/drivers/net/wireless/ath/ath5k/qcu.c
> index abe36c0..9122a85 100644
> --- a/drivers/net/wireless/ath/ath5k/qcu.c
> +++ b/drivers/net/wireless/ath/ath5k/qcu.c
> @@ -408,12 +408,13 @@ int ath5k_hw_reset_tx_queue(struct ath5k_hw *ah, unsigned int queue)
> break;
>
> case AR5K_TX_QUEUE_CAB:
> + /* XXX: use BCN_SENT_GT, if we can figure out how */
> AR5K_REG_ENABLE_BITS(ah, AR5K_QUEUE_MISC(queue),
> - AR5K_QCU_MISC_FRSHED_BCN_SENT_GT |
> + AR5K_QCU_MISC_FRSHED_DBA_GT |
> AR5K_QCU_MISC_CBREXP_DIS |
> AR5K_QCU_MISC_CBREXP_BCN_DIS);
>
> - ath5k_hw_reg_write(ah, ((AR5K_TUNE_BEACON_INTERVAL -
> + ath5k_hw_reg_write(ah, ((tq->tqi_ready_time -
> (AR5K_TUNE_SW_BEACON_RESP -
> AR5K_TUNE_DMA_BEACON_RESP) -
> AR5K_TUNE_ADDITIONAL_SWBA_BACKOFF) * 1024) |
It would be great if we had some feedback from Atheros on BCN_SENT_GT...
Acked-by: Nick Kossifidis <mickflemm@xxxxxxxxx>
--
GPG ID: 0xD21DB2DB
As you read this post global entropy rises. Have Fun ;-)
Nick
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