On Tue, Jul 28, 2015 at 10:42 PM, Grumbach, Emmanuel <emmanuel.grumbach@xxxxxxxxx> wrote: > > > 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. AP needs to allocate large RX buffers to accomodate AMSDU + AMPDU, no? > 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. I understand from AP point of view, but what about the local HW? Don't we need HW support to handle this A-MSDU in AMPDU? (or) the driver should handle this support in ampdu_action based on the amsdu flag? -- 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
