Re: ath: DMA failed to stop in 10 ms AR_CR=0x00000024 AR_DIAG_SW=0x02000020DMADBG_7=0x00008040

[Justin P. Mattock]

On 03/20/2012 01:29 AM, Sujith Manoharan wrote:
> Justin P. Mattock wrote:
> > yeah this works:
> >
> > eading symbols from
> > /home/kernel/linux-next/drivers/net/wireless/ath/ath9k/ath9k.o...done.
> > (gdb) l *(ath_tx_start+0x284)
> > 0xcad4 is in ath_tx_start (drivers/net/wireless/ath/ath9k/xmit.c:1878).
> > 1873			ieee80211_is_data_qos(hdr->frame_control)) {
> > 1874			tidno = ieee80211_get_qos_ctl(hdr)[0]&
> > 1875				IEEE80211_QOS_CTL_TID_MASK;
> > 1876			tid = ATH_AN_2_TID(txctl->an, tidno);
> > 1877	
> > 1878			WARN_ON(tid->ac->txq != txctl->txq);
> > 1879		}
> > 1880	
> > 1881		if ((tx_info->flags&  IEEE80211_TX_CTL_AMPDU)&&  tid) {
> > 1882			/*
> > (gdb)
>
> Can you try this patch ?
>
> From: Sujith Manoharan<c_manoha@xxxxxxxxxxxxxxxx>
> Date: Tue, 20 Mar 2012 13:51:26 +0530
> Subject: [PATCH] ath9k: Use HW HT capabilites properly
>
> The commit "ath9k: Remove aggregation flags" changed how
> nodes were being initialized. Use the HW HT cap bits
> to initialize/de-initialize nodes, else we would be
> accessing an uninitialized entry during a suspend/resume cycle,
> resulting in a panic.
>
> Reported-by: Justin P. Mattock<justinmattock@xxxxxxxxx>
> Signed-off-by: Sujith Manoharan<c_manoha@xxxxxxxxxxxxxxxx>
> ---
>   drivers/net/wireless/ath/ath9k/main.c |    4 ++--
>   1 file changed, 2 insertions(+), 2 deletions(-)
>
> diff --git a/drivers/net/wireless/ath/ath9k/main.c b/drivers/net/wireless/ath/ath9k/main.c
> index 3879485..215eb25 100644
> --- a/drivers/net/wireless/ath/ath9k/main.c
> +++ b/drivers/net/wireless/ath/ath9k/main.c
> @@ -640,7 +640,7 @@ static void ath_node_attach(struct ath_softc *sc, struct ieee80211_sta *sta,
>   	an->sta = sta;
>   	an->vif = vif;
>
> -	if (sta->ht_cap.ht_supported) {
> +	if (sc->sc_ah->caps.hw_caps&  ATH9K_HW_CAP_HT) {
>   		ath_tx_node_init(sc, an);
>   		an->maxampdu = 1<<  (IEEE80211_HT_MAX_AMPDU_FACTOR +
>   				     sta->ht_cap.ampdu_factor);
> @@ -659,7 +659,7 @@ static void ath_node_detach(struct ath_softc *sc, struct ieee80211_sta *sta)
>   	an->sta = NULL;
>   #endif
>
> -	if (sta->ht_cap.ht_supported)
> +	if (sc->sc_ah->caps.hw_caps&  ATH9K_HW_CAP_HT)
>   		ath_tx_node_cleanup(sc, an);
>   }

I would have to say this patch above does get rid of this crash I was 
seeing. as a quick test I simply connect to a WPA network, then connect 
to an open network going back and forth triggers this freeze for me 
after applying this I am able to toggle back and forth without a freeze.

Thanks!

Justin P. Mattock
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