[ath9k-devel] [PATCH] ath9k: Configure beacons for AP vif if this has not happened yet

[Ben Greear <greearb@candelatech.com>]

Any idea how far back this needs to be backported for stable?

Just to 4.0?

Thanks,
Ben

On 03/13/2015 07:27 AM, Felix Fietkau wrote:
> On 2015-03-13 14:33, Benjamin Berg wrote:
>> Right now there is a bug where beaconing might not be enabled correctly
>> if the user has configuring multiple VIFs.
>> The issue surfaces if the userspace first creates the AP devices and
>> only then configures the first VIF (ath9k_bss_info_changed is called).
>> In this case the current ath9k_allow_beacon_config implementation will
>> not allow configuration as multiple AP VIFs are already present and
>> beaconing is never configured in the driver.
>>
>> This issue was probably introduced back in 2012 by commit ef4ad6336
>> "ath9k: Cleanup beacon logic". The fix in this patch simply checks
>> whether beaconing has been configured yet (or configuration is scheduled)
>> and allows the configuration in that case. This works around the issue
>> here, but I have no idea whether it is a sane solution.
>>
>> Signed-off-by: Benjamin Berg <benjamin@sipsolutions.net>
> I sent the following patch yesterday - I think it addresses the exact 
> same issue. Please test it to see if it works for you as well.
> 
> Subject: [PATCH 4.0] ath9k: fix tracking of enabled AP beacons
> 
> sc->nbcnvifs tracks assigned beacon slots, not enabled beacons.
> Therefore, it cannot be used to decide if cur_conf->enable_beacon (bool)
> should be updated, or if beacons have been enabled already.
> With the current code (depending on the order of calls), beacons often
> do not get enabled in an AP+STA setup.
> To fix tracking of enabled beacons, convert cur_conf->enable_beacon to a
> bitmask of enabled beacon slots.
> 
> Cc: stable at vger.kernel.org
> Signed-off-by: Felix Fietkau <nbd@openwrt.org>
> ---
>  drivers/net/wireless/ath/ath9k/beacon.c | 20 ++++++++++++--------
>  drivers/net/wireless/ath/ath9k/common.h |  2 +-
>  2 files changed, 13 insertions(+), 9 deletions(-)
> 
> diff --git a/drivers/net/wireless/ath/ath9k/beacon.c b/drivers/net/wireless/ath/ath9k/beacon.c
> index cb366ad..f50a6bc 100644
> --- a/drivers/net/wireless/ath/ath9k/beacon.c
> +++ b/drivers/net/wireless/ath/ath9k/beacon.c
> @@ -219,12 +219,15 @@ void ath9k_beacon_remove_slot(struct ath_softc *sc, struct ieee80211_vif *vif)
>  	struct ath_common *common = ath9k_hw_common(sc->sc_ah);
>  	struct ath_vif *avp = (void *)vif->drv_priv;
>  	struct ath_buf *bf = avp->av_bcbuf;
> +	struct ath_beacon_config *cur_conf = &sc->cur_chan->beacon;
>  
>  	ath_dbg(common, CONFIG, "Removing interface at beacon slot: %d\n",
>  		avp->av_bslot);
>  
>  	tasklet_disable(&sc->bcon_tasklet);
>  
> +	cur_conf->enable_beacon &= ~BIT(avp->av_bslot);
> +
>  	if (bf && bf->bf_mpdu) {
>  		struct sk_buff *skb = bf->bf_mpdu;
>  		dma_unmap_single(sc->dev, bf->bf_buf_addr,
> @@ -521,8 +524,7 @@ static bool ath9k_allow_beacon_config(struct ath_softc *sc,
>  	}
>  
>  	if (sc->sc_ah->opmode == NL80211_IFTYPE_AP) {
> -		if ((vif->type != NL80211_IFTYPE_AP) ||
> -		    (sc->nbcnvifs > 1)) {
> +		if (vif->type != NL80211_IFTYPE_AP) {
>  			ath_dbg(common, CONFIG,
>  				"An AP interface is already present !\n");
>  			return false;
> @@ -616,12 +618,14 @@ void ath9k_beacon_config(struct ath_softc *sc, struct ieee80211_vif *vif,
>  	 * enabling/disabling SWBA.
>  	 */
>  	if (changed & BSS_CHANGED_BEACON_ENABLED) {
> -		if (!bss_conf->enable_beacon &&
> -		    (sc->nbcnvifs <= 1)) {
> -			cur_conf->enable_beacon = false;
> -		} else if (bss_conf->enable_beacon) {
> -			cur_conf->enable_beacon = true;
> -			ath9k_cache_beacon_config(sc, ctx, bss_conf);
> +		bool enabled = cur_conf->enable_beacon;
> +
> +		if (!bss_conf->enable_beacon) {
> +			cur_conf->enable_beacon &= ~BIT(avp->av_bslot);
> +		} else {
> +			cur_conf->enable_beacon |= BIT(avp->av_bslot);
> +			if (!enabled)
> +				ath9k_cache_beacon_config(sc, ctx, bss_conf);
>  		}
>  	}
>  
> diff --git a/drivers/net/wireless/ath/ath9k/common.h b/drivers/net/wireless/ath/ath9k/common.h
> index 2b79a56..d237373 100644
> --- a/drivers/net/wireless/ath/ath9k/common.h
> +++ b/drivers/net/wireless/ath/ath9k/common.h
> @@ -54,7 +54,7 @@ struct ath_beacon_config {
>  	u16 dtim_period;
>  	u16 bmiss_timeout;
>  	u8 dtim_count;
> -	bool enable_beacon;
> +	u8 enable_beacon;
>  	bool ibss_creator;
>  	u32 nexttbtt;
>  	u32 intval;
> -- 2.2.2 --
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> 


-- 
Ben Greear <greearb@candelatech.com>
Candela Technologies Inc  http://www.candelatech.com