On 07/28/2015 02:35 PM, Grumbach, Emmanuel wrote: >> On Tue, Jul 21, 2015 at 1:12 AM, Emmanuel Grumbach >> <emmanuel.grumbach@xxxxxxxxx> wrote: >>> diff --git a/net/mac80211/agg-tx.c b/net/mac80211/agg-tx.c index >>> c8ba2e7..a758eb84 100644 >>> --- a/net/mac80211/agg-tx.c >>> +++ b/net/mac80211/agg-tx.c >>> @@ -97,7 +97,8 @@ static void ieee80211_send_addba_request(struct >> ieee80211_sub_if_data *sdata, >>> mgmt->u.action.u.addba_req.action_code = >>> WLAN_ACTION_ADDBA_REQ; >>> >>> mgmt->u.action.u.addba_req.dialog_token = dialog_token; >>> - capab = (u16)(1 << 1); /* bit 1 aggregation policy */ >>> + capab = (u16)(1 << 0); /* bit 0 A-MSDU support */ >> Shouldn't this be based on HW capability? We can add couple of more _HW_ >> flags for TX and RX and populate this based on that? > Why? > What will happen if we ask for A-MSDU inside A-MPDU and we won't do A-MSDU? > Worst case, the AP will deny this and will clear that bit in its response. I feel that my response was accurate, but the wording wasn't precise enough. We have two possibilities: 1) the AP does support A-MSDU in A-MPDU 2) the AP does not support A-MSDU in A-MPDU In the first case, the AP will reply with that bit set and the client can choose to send A-MSDU or not. I don't think that the AP needs to allocate anything special to support A-MSDU in A-MPDU, so it is free to ask. In the second case, the AP will reply with that same bit clear in the AddBA response, and mac0211 / driver will know not to send A-MSDU in A-MPDU (which the driver doesn't support in the case you were describing - so this is a no-op). The only concern you may have is about APs that would decline the AddBA request because of that bit. That doesn't seem to happen since a lot of vendors use A-MSDU in A-MPDU. -- To unsubscribe from this list: send the line "unsubscribe linux-wireless" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
