On Mon, Jan 23, 2012 at 6:44 PM, Andreas Hartmann
<andihartmann@xxxxxxxxxxxxxxx> wrote:
> Am Mon, 23 Jan 2012 17:36:57 +0100
> schrieb Helmut Schaa <helmut.schaa@xxxxxxxxxxxxxx>:
>
>> On Mon, Jan 23, 2012 at 5:03 PM, Andreas Hartmann
>> <andihartmann@xxxxxxxxxx> wrote:
>> > Helmut Schaa schrieb:
>> >> On Fri, Jan 20, 2012 at 8:29 AM, Andreas Hartmann
>> >> <andihartmann@xxxxxxxxxxxxxxx> wrote:
>> >>> All in one: Your workaround was a good idea, but unfortunately it
>> >>> doesn't "solve" / workaround the problem introduced with the patch
>> >>> "mac80211: retry sending failed BAR frames later instead of tearing
>> >>> down aggr" [1]. I don't know off any other solution at this time as to revert it.
>> >>
>> >> Ok, so we've got at least one hw issue here: rt2800 is not able to report
>> >> correct ACK state of BARs :(
>> >>
>> >> The interesting bit is that the legacy drivers tear the BA session down as
>> >> soon as the first AMPDU subframe failed. That's the same behavior as
>> >> mac80211 had before the mentioned patch.
>> >>
>> >> So, let's assume the generic way Felix implemented works for other devices
>> >> (like ath9k) we could go with a workaround inside rt2x00 to tear down
>> >> the BA session as soon as the first AMPDU frame failed.
>> >>
>> >> Mind to try that one (not even compile tested though :) ).
>> >
>> > hdr is missing. I tried to derive it like this:
>> >
>> > struct ieee80211_hdr *hdr=(void*)entry->skb->data;
>>
>> Looks correct but you should put it right before the ieee80211_is_data_qos check
>> not at the start of the function ...
>
> I did it like this:
>
> --- drivers/net/wireless/rt2x00/rt2x00dev.c.orig 2012-01-23 16:50:03.188718671 +0100
> +++ drivers/net/wireless/rt2x00/rt2x00dev.c 2012-01-23 18:11:56.248553764 +0100
> @@ -388,8 +388,17 @@
> tx_info->status.ampdu_len = 1;
> tx_info->status.ampdu_ack_len = success ? 1 : 0;
>
> - if (!success)
> - tx_info->flags |= IEEE80211_TX_STAT_AMPDU_NO_BACK;
> + struct ieee80211_hdr *hdr = (void*) entry->skb->data;
> + if (!success && tx_info->control.sta != NULL && ieee80211_is_data_qos(hdr->frame_control)) {
> + /*
> + * Tear down BA session
> + */
> + struct ieee80211_sta *sta = tx_info->control.sta;
> + u8 *qc = ieee80211_get_qos_ctl(hdr);
> + int tid = *qc & IEEE80211_QOS_CTL_TID_MASK;
> +
> + ieee80211_stop_tx_ba_session(sta, tid);
> + }
> }
>
> if (rate_flags & IEEE80211_TX_RC_USE_RTS_CTS) {
>
>
> but the machine does crash anyway. Could hdr be null, too?
Ok, I'll do some testing as soon as time allows and get back to you then.
Helmut
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