"Greenman, Gregory" <gregory.greenman@xxxxxxxxx> writes: > On Sun, 2023-04-23 at 10:55 +0200, Uwe Kleine-König wrote: >> Hello Gregory, >> >> there is a thread on debian-user-german@xxxxxxxxxxxxxxxx[1] about >> broken wifi on Thinkpads when they are supposed to be connected to the >> hotspots available in ICE4 trains. The mailing lists language is German >> and the thread is long, so I sum up the problem: >> >> - It only affects the wifi equipment in ICE4 trains, the older ones work >> fine. >> >> - Can be seen at least on >> - Jürgen's laptop (Intel Corporation Wireless 8260 [8086:24f3] (rev 3a)) >> - Marc's Thinkpad X260 (Intel Corporation Wireless 8260 [8086:24f3] (rev 3a)) >> - Uwe's Thinkpad T460p (Intel Corporation Wireless 8260 [8086:24f3] (rev 3a)) >> >> - Other Thinkpads with a Realtek-Chip doesn't show the problem >> >> - Works on puppy-Linux with 4.19.23, however Debian with 4.19.0-18 is >> also broken. >> >> - The OP provided a syslog dump at >> https://lists.debian.org/msgid-search/75ad7ff2-ef25-90cd-2cb3-1f49f3e4909e@xxxxxxxxx >> >> I don't reproduce it here, but the gist seems to be: >> >> Jun 23 15:44:53 lina kernel: [ 1006.011129] wlp1s0: deauthenticated from 3c:51:0e:56:32:80 (Reason: 2=PREV_AUTH_NOT_VALID) >> >> - it seems to help to do: >> $ cat /etc/modprobe.d/iwlwifi.conf >> options iwlwifi 11n_disable=1 swcrypto=0 bt_coex_active=0 power_save=0 >> options iwlmvm power_scheme=1 >> options iwlwifi d0i3_disable=1 >> options iwlwifi uapsd_disable=1 >> options iwlwifi lar_disable=1 >> >> I added all participants of said thread to Cc, in case I forgot >> something relevant. >> >> Tomorrow I might have the opportunity to test and reproduce the problem >> (I don't know if my train will be an ice4 or one of the older ones >> though.) >> >> I wonder if there is something you want me to test. Without further >> input I will try with the modprobe options and check for a minimal >> subset of them that makes the problem disappear. >> >> Is there something I can do to make the problem better understandable >> for someone who knows about the hardware? Or to find out the critical >> detail about the wifi hotspot that triggers the problem? >> >> Best regards >> Uwe >> >> [1] https://lists.debian.org/msgid-search/da8c1552-6bcb-14c3-0e86-abcb835ec350@xxxxxxxxx >> > > Hi Uwe, > > Based on the log, I can understand that it had successfully connected > to the AP (supplicant management interface state: associating -> > completed); then there're some DHCP errors and eventually the AP sends > a deauth. If it's DHCP failing it could be an issue with multicast traffic? I've definitely seen multicast failing on busy networks because it is set to too low a rate and gets overwhelmed, which leads to DHCP (and ARP) failures while unicast traffic works fine. It's probably not (only) a network issue if it works fine with other drivers, but maybe there's some kind of interaction between the driver and multicast? Just a thought :) -Toke
