Re: [PATCH] mac80211: make ieee80211_send_bar available for drivers

On Sat, 2011-08-20 at 20:26 +0200, Felix Fietkau wrote:

On 2011-08-20 3:53 PM, Felix Fietkau wrote:

quoted

To properly maintain the peer's block ack window, the driver needs to be
able to control the new starting sequence number that is sent along with
the BlockAckReq frame.

Signed-off-by: Felix Fietkau<redacted>
---
turns out that I will need this change in mac80211 anyway to properly
handle a few corner cases wrt. aggregation and off-channel activity.

When ath9k goes off-channel it may need to drop some packets that are
still part of the BAW, but at that point in time it would be a very
bad idea to try to send BAR frames. Instead I want to send the BAR
after switching back to the primary channel as a kind of barrier before
sending more packets.

Johannes, do you think it would make the driver API better if instead of 
exporting this function, I add an ieee80211_bar_get function (similar to 
ieee80211_nullfunc_get or ieee80211_probereq_get) to avoid concerns over 
the missing _ni variant or the weird callchain from the driver back into 
the tx function?

Probably not -- especially since that might be tricky wrt. rate control?

I don't really know. Seems that the call back from the driver into
itself is possible with mesh too -- I guess we need to decide whether
that is something we do or not.

johannes