On Tue, Mar 3, 2015 at 2:46 PM, Johannes Berg <johannes@xxxxxxxxxxxxxxxx> wrote: > On Tue, 2015-02-10 at 12:48 +0100, Michal Kazior wrote: >> Some APs experience problems when working with >> U-APSD. Decreasing the probability of that >> happening by using legacy mode for all ACs but VO >> isn't enough. >> >> Cisco 4410N originally forced us to enable VO by >> default only because it treated non-VO ACs as >> legacy. >> >> However some APs (notably Netgear R7000) silently >> reclassify packets to different ACs. Since u-APSD >> ACs require trigger frames for frame retrieval >> clients would never see some frames (e.g. ARP >> responses) or would fetch them accidentally after >> a long time. > > This makes me a little sad, but I've applied this and even added a Cc > stable tag due to the interoperability issues. > Mixed mode (uapsd + legacy) is not really the optimal configuration, where we expect STA to send trigger frames periodically to retrieve the DL packets (especially very first packet). But still if we want power save, i suggest going for All u-apsd (0xF), so that AP will inform us by setting the TIM bit and we can retrieve the first frame. (We have this patch internally and it works well). -- 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
