On Thu, 2020-01-30 at 14:55 +0000, Jean-Pierre TOSONI wrote: > Maybe you need to put some distance between the 3 devices. > We experienced this kind of problem on radios close to each other > (around 10cm). > It was due to radio signals inducing themselves in the PCB of another > nearby radio, causing the other radio to badly transmit and receive. > > > > > -----Message d'origine----- > > De : linux-wireless-owner@xxxxxxxxxxxxxxx [mailto:linux-wireless-ow > > ner@xxxxxxxxxxxxxxx] De la part de > > Marlon Smith > > Envoyé : mercredi 29 janvier 2020 19:40 > > À : linux-wireless@xxxxxxxxxxxxxxx > > Objet : Strange performance issue when using two devices at once > > > > Hi everyone, > > > > I have two RT5370 devices connected to the same access point. Both > > devices are very slow, but the instant I disconnect one device, the > > other speeds up by a factor of 10. > > > > The really strange part is that one device will perform slowly even > > if > > the other device is basically idle! I've confirmed this with a > > packet > > sniffer. > > > > I've been trying to do some debugging, and I've found that when > > both > > devices are connected to the access point, they report a large > > number > > of duplicate frames. I added some debug output > > in ieee80211_rx_h_check_dup() to confirm that this only happens > > while > > both devices are connected. The packet sniffer also shows a large > > number of retries while this is occurring. > > > > Using backports 5.3-rc4 for this, but also tested on 4.14-rc2. > > > > I did post about this previously on this mailing list (RT5370 > > performance issues), but I thought I'd post again with this new > > information and more descriptive title. I'm a little bit stuck on > > this > > for a while now, so any ideas are much appreciated. > > > > Thanks! > > > > Marlon Thanks for the reply Jean-Pierre. I just discovered this morning that if I change the MAC address of one of the devices, they both perform well. So I'm wondering if it is a driver issue. However I will keep this in mind, as I often do have multiple devices together in close proximity.
