rtw88: USB devices randomly stop receiving anything

[Bitterblue Smith <rtl8821cerfe2@gmail.com>]

Hi,

I have this problem with RTL8811CU, RTL8723DU, RTL8811AU, RTL8812AU.
I assume all USB devices are affected. If I have qBittorrent running,
the wifi stops working after a few hours:

Sep 24 00:48:21 ideapad2 wpa_supplicant[1290]: wlp3s0f3u2i2: CTRL-EVENT-BEACON-LOSS
Sep 24 00:48:21 ideapad2 kernel: rtw_8723du 1-2:1.2: failed to get tx report from firmware
Sep 24 00:48:23 ideapad2 wpa_supplicant[1290]: wlp3s0f3u2i2: CTRL-EVENT-BEACON-LOSS
Sep 24 00:48:23 ideapad2 kernel: rtw_8723du 1-2:1.2: failed to get tx report from firmware
Sep 24 00:48:25 ideapad2 wpa_supplicant[1290]: wlp3s0f3u2i2: CTRL-EVENT-BEACON-LOSS
Sep 24 00:48:25 ideapad2 kernel: rtw_8723du 1-2:1.2: failed to get tx report from firmware
Sep 24 00:48:27 ideapad2 wpa_supplicant[1290]: wlp3s0f3u2i2: CTRL-EVENT-BEACON-LOSS
Sep 24 00:48:27 ideapad2 kernel: rtw_8723du 1-2:1.2: failed to get tx report from firmware
Sep 24 00:48:29 ideapad2 wpa_supplicant[1290]: wlp3s0f3u2i2: CTRL-EVENT-BEACON-LOSS
Sep 24 00:48:29 ideapad2 kernel: rtw_8723du 1-2:1.2: failed to get tx report from firmware
Sep 24 00:48:31 ideapad2 wpa_supplicant[1290]: wlp3s0f3u2i2: CTRL-EVENT-BEACON-LOSS
Sep 24 00:48:31 ideapad2 kernel: rtw_8723du 1-2:1.2: failed to get tx report from firmware
Sep 24 00:48:33 ideapad2 wpa_supplicant[1290]: wlp3s0f3u2i2: CTRL-EVENT-BEACON-LOSS
Sep 24 00:48:33 ideapad2 kernel: rtw_8723du 1-2:1.2: failed to get tx report from firmware
Sep 24 00:48:35 ideapad2 wpa_supplicant[1290]: wlp3s0f3u2i2: CTRL-EVENT-BEACON-LOSS
Sep 24 00:48:35 ideapad2 kernel: rtw_8723du 1-2:1.2: failed to get tx report from firmware
Sep 24 00:48:37 ideapad2 wpa_supplicant[1290]: wlp3s0f3u2i2: CTRL-EVENT-BEACON-LOSS
Sep 24 00:48:37 ideapad2 kernel: rtw_8723du 1-2:1.2: failed to get tx report from firmware
Sep 24 00:48:39 ideapad2 wpa_supplicant[1290]: wlp3s0f3u2i2: CTRL-EVENT-BEACON-LOSS
Sep 24 00:48:39 ideapad2 kernel: rtw_8723du 1-2:1.2: failed to get tx report from firmware
Sep 24 00:48:41 ideapad2 wpa_supplicant[1290]: wlp3s0f3u2i2: CTRL-EVENT-BEACON-LOSS
Sep 24 00:48:41 ideapad2 kernel: rtw_8723du 1-2:1.2: failed to get tx report from firmware
Sep 24 00:48:42 ideapad2 wpa_supplicant[1290]: wlp3s0f3u2i2: CTRL-EVENT-DISCONNECTED bssid=... reason=4 locally_generated=1
Sep 24 00:48:42 ideapad2 wpa_supplicant[1290]: wlp3s0f3u2i2: Added BSSID ... into ignore list, ignoring for 10 seconds
Sep 24 00:48:42 ideapad2 NetworkManager[433]: <info>  [1727128122.0377] device (wlp3s0f3u2i2): supplicant interface state: completed -> disconnected
Sep 24 00:48:45 ideapad2 NetworkManager[433]: <info>  [1727128125.6030] device (wlp3s0f3u2i2): supplicant interface state: disconnected -> scanning
Sep 24 00:48:47 ideapad2 wpa_supplicant[1290]: wlp3s0f3u2i2: Removed BSSID ... from ignore list (clear)
Sep 24 00:48:47 ideapad2 wpa_supplicant[1290]: wlp3s0f3u2i2: SME: Trying to authenticate with ... (SSID='...' freq=2472 MHz)
Sep 24 00:48:50 ideapad2 kernel: wlp3s0f3u2i2: authenticate with ... (local address=,,,)
Sep 24 00:48:51 ideapad2 NetworkManager[433]: <info>  [1727128131.2488] device (wlp3s0f3u2i2): supplicant interface state: scanning -> authenticating
Sep 24 00:48:51 ideapad2 kernel: wlp3s0f3u2i2: send auth to ... (try 1/3)
Sep 24 00:48:51 ideapad2 kernel: rtw_8723du 1-2:1.2: failed to get tx report from firmware
Sep 24 00:48:52 ideapad2 kernel: wlp3s0f3u2i2: send auth to ... (try 2/3)
Sep 24 00:48:52 ideapad2 kernel: rtw_8723du 1-2:1.2: failed to get tx report from firmware
Sep 24 00:48:53 ideapad2 kernel: wlp3s0f3u2i2: send auth to ... (try 3/3)
Sep 24 00:48:53 ideapad2 kernel: rtw_8723du 1-2:1.2: failed to get tx report from firmware
Sep 24 00:48:54 ideapad2 kernel: wlp3s0f3u2i2: authentication with ... timed out

After this all scans return nothing. The chip is still alive,
though. The LED blinks during the scans (it's hardware-controlled)
and another device in monitor mode can see the probe requests.

I confirmed that even C2H stop coming. I used aireplay-ng to send
some authentication or association frames (can't remember) which
require TX ACK report. I saw "failed to get tx report from firmware"
and no C2H.

While qBittorrent is needed to trigger this bug, simply downloading
a random Linux iso did not do the job. "Other" torrents did. It's
unclear why. Maybe it's uploading that triggers the bug.

I left iperf3 running all day and nothing happened. Only qBittorrent
can break it.

RTL8822CE doesn't have this problem. I can use qBittorrent with it
just fine.

I mounted debugfs and dumped the MAC registers during a scan using
this command:

for i in {00..20}; do sleep 0.5; cat /sys/kernel/debug/ieee80211/phy2/rtw88/mac_{0..7} > dead-$i.txt; done

I thought maybe some RX URBs failed silently and rtw88 stopped
sending them to the device (== stopped requesting data from it),
but that's not the case. [1]

I have the device in this state right now. Is there anything else
I should look at?


[1] https://git.kernel.org/pub/scm/linux/kernel/git/stable/linux.git/tree/drivers/net/wireless/realtek/rtw88/usb.c?h=v6.10.11&id=25eaef533bf3ccc6fee5067aac16f41f280e343e#n641