Hi, So I just ran into this problem with a colleague again; we don't have good visibility into why in the wifi stack a packet is dropped. In the network stack we have skb drop reasons for (part of?) this, but we don't really use this in wifi/mac80211 yet. Unfortunately we have probably >100 distinct drop reasons in the wifi stack, so annotating those is not only tedious, it would also double the list of SKB drop reasons from currently ~75. Any good ideas? I even thought about just encoding the line number wherever we use RX_DROP_UNUSABLE / RX_DROP_MONITOR, but that's kind of awkward too. Obviously we could change the internal API to completely get rid of enum ieee80211_rx_result and use enum skb_drop_reason instead, but then we'd probably need to carve out some space to also differentiate DROP_MONITOR and DROP_UNUSABLE, perhaps something like SKB_DROP_REASON_MAC80211_MASK 0x03ff0000 SKB_DROP_REASON_MAC80211_TYPE_MASK 0x03000000 SKB_DROP_REASON_MAC80211_TYPE_UNUSABLE 0x01000000 SKB_DROP_REASON_MAC80211_TYPE_MONITOR 0x02000000 SKB_DROP_REASON_MAC80211_DUP (SKB_DROP_REASON_MAC80211_TYPE_UNUSABLE | 1) SKB_DROP_REASON_MAC80211_BAD_BIP_KEYIDX (SKB_DROP_REASON_MAC80211_TYPE_MONITOR | 1) etc. That'd be a LOT of annotations (and thus work) though, and a lot of new IDs/names, for something that's not really used all that much, i.e. a file number / line number within mac80211 would be completely sufficient, so the alternative could be to just have a separate tracepoint inside mac80211 with a line number or so? Anyone have any great ideas? Thanks, johannes
