Re: ath: DMA failed to stop in 10 ms AR_CR=0x00000024AR_DIAG_SW=0x02000020 DMADBG_7=0x00008040

[Mohammed Shafi]

Hi Sujith/Justin,

On Tue, Mar 20, 2012 at 1:59 PM, Sujith Manoharan
<c_manoha@xxxxxxxxxxxxxxxx> 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 ?

just found out that 'ht_supported' may not  be set, if assoc response
does not has ht_cap IE (or) if we could not parse it (why), then the
driver won't initialize those tid related structures ath_tx_node_init,
while we later access them in ath_tx_start. so this should fix the
issue.

>
> 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);
>  }
>
> --
> 1.7.9.4
>



-- 
thanks,
shafi
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/