On Tue, 2011-02-01 at 23:02 +0530, Rajkumar Manoharan wrote: > While leaving oper channel, STA informs sleep state to AP to > stop sending data. Till sending ack for the nullfunc, AP > continues to send the data to STA which restarts ps_timer that > is causing unnecessary nullfunc exchange on timer expiry > when the STA was already moved to offchannel. So don't restart ps_timer > on data reception during scan. This issue was identified by > the following warning. > > WARNING: at net/mac80211/tx.c:661 invoke_tx_handlers+0xf07/0x1330 [mac80211] > wlan0: Dropped data frame as no usable bitrate found while scanning and > associated. Target station: 00:03:7f:0b:a6:1b on 5 GHz band > Call Trace: > [<ffffffffa0413ba7>] invoke_tx_handlers+0xf07/0x1330 [mac80211] > [<ffffffffa0414056>] ieee80211_tx+0x86/0x2c0 [mac80211] > [<ffffffffa0414345>] ieee80211_xmit+0xb5/0x1d0 [mac80211] > [<ffffffffa04037e0>] ieee80211_dynamic_ps_enable_work+0x0/0xb0 [mac80211] > [<ffffffffa04158cf>] ieee80211_tx_skb+0x4f/0x60 [mac80211] > [<ffffffffa04026e6>] ieee80211_send_nullfunc+0x46/0x60 [mac80211] > [<ffffffffa0403885>] ieee80211_dynamic_ps_enable_work+0xa5/0xb0 [mac80211] This mostly makes sense -- but how about HW scan? Can drivers have HW scan and still require powersave stuff this way? With HW scan, frames can come in properly while "local->scanning" is non-zero. But I suppose even during a HW scan we don't want mac80211 to modify PS state anyway, so I guess it's fine. johannes -- 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
