On Mon, May 26, 2014 at 03:37:36PM +0000, Matthias Fend wrote: > Hello, > > Here are some updates concerning my current issues. > > > -----Ursprüngliche Nachricht----- > > Von: linux-wireless-owner@xxxxxxxxxxxxxxx [mailto:linux-wireless- > > owner@xxxxxxxxxxxxxxx] Im Auftrag von Matthias Fend > > Gesendet: Freitag, 23. Mai 2014 14:25 > > An: linux-wireless@xxxxxxxxxxxxxxx > > Betreff: rt2x00: Ralink RT5572 very high peak current consumption > > > > Hello Ralink experts, > > > > I recognized spurious problems with Ralink RT5572 USB-dongles when using > > this dongles as access point in 5G band. > > The problems may appear as short usb disconnect-connect events or failed > > vendor request messages at different offsets with different error codes or > > will not appear for days ;) During error research I noticed that, most likely > > during the beacon send time (100ms interval), there are very high peak > > currents in the supply of the USB-dongle. > > > > I tried it with two different dongles, the base current for all three is in the > > range of ~200mA: > > Buffalo WI-U2-300D: Peak ~1A > > TP-Link TL-WDN3200: Peak ~1.2mA > > > > We could reproduce this issue on two different machines (x86 and arm), did > > test with kernel versions 3.10.19, 3.13.0 and 3.14.4 tried hostapd-2.0 and > > hostapd-2.1 and loaded chip firmware version V0.29, V0.33 and V0.35. > > > > As a comparison I also created an 5G access point setup with a windows7 > > machine - all with the latest drivers from the manufacturer webpage. > > Buffalo WI-U2-300D: Peak 330mA > > TP-Link TL-WDN3200: Peak 330mA > > Which seems more legit than the values from the linux setups. > > > > The access point functionality itself worked with every tested combination, > > but there is definitively something wrong. > > I also started to grab the usb communication of the windows driver to see if > > there is an obvious difference in some of the written registers. > > But this kind of reverse engineering is not as easy since the windows driver > > does not write the same registers as the linux drivers but write some others - > > and of course I have no datasheet/register description. > > > > Until now the only interesting thing I found out is that the linux driver writes > > 0x00000082 to the TXOP_HLDR_ET (0x1608) register whereas the windows > > driver uses a value of 0x0000000a. Changing this register during runtime in a > > linux system reduces the current peaks to 50 percent of their previous value. > > But there is still something else wrong. > > > > So, in my despair I try to get help in any form (hints, datasheets/manuals, > > ideas, experience, ...). > > I found out that the discovered high current peaks are somehow related to invalidated beacons. > Usually I can see 1 block with a normal tx-condition current followed by 7 additional blocks with high current peaks. > For a test I copied the beacon data from HW_BEACON_BASE0 to HW_BEACON_BASE2 and then the first and the third beacon block have normal current values while the others still generate high current peaks > > It seems that setting all five words of the TXWI at the beacon base does not complete disable the generation of this beacon. > If I modify the TXIW_W0 of the disabled beacons to 0x40000000 (set TXWI_W0_PHYMODE as in the really used beacon) then the current consumption does not exceed the usual value. But it seems that there is still a short activity for this beacon which, in my opinion, should not be the case. > > So, currently I'm wondering about two things: > -)How do I completely turn off unused beacons (from the measurements with the windows setup I know that this should be somehow possible)? Perhaps this could be MULTI_BCN_NUM value in MAC_BSSID_DW1 register. Try below patch. If it would help we will need to change way we clear/setup beacons on multiple BSSes, because seems that HW send MULTI_BCN_NUM beacons from first registers. Stanislaw diff --git a/drivers/net/wireless/rt2x00/rt2800lib.c b/drivers/net/wireless/rt2x00/rt2800lib.c index c17fcf2..2e799d5 100644 --- a/drivers/net/wireless/rt2x00/rt2800lib.c +++ b/drivers/net/wireless/rt2x00/rt2800lib.c @@ -1556,7 +1556,7 @@ void rt2800_config_intf(struct rt2x00_dev *rt2x00dev, struct rt2x00_intf *intf, if (!is_zero_ether_addr((const u8 *)conf->bssid)) { reg = le32_to_cpu(conf->bssid[1]); rt2x00_set_field32(®, MAC_BSSID_DW1_BSS_ID_MASK, 3); - rt2x00_set_field32(®, MAC_BSSID_DW1_BSS_BCN_NUM, 7); + rt2x00_set_field32(®, MAC_BSSID_DW1_BSS_BCN_NUM, 0); conf->bssid[1] = cpu_to_le32(reg); } -- 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
