Bitterblue Smith <rtl8821cerfe2@xxxxxxxxx> wrote: > Hi, > > I ran into a problem with the RTL8812BU. If I load it a bit in USB 3 > mode, like with "iperf3 -c 192.168.0.1 -R -t 60" the connection often > stops working. It may take a few tries. It still receives beacons but > the AP can't be pinged anymore. > > Looking at the registers with > "watch cat /sys/kernel/debug/ieee80211/phy*/rtw88/mac_2", I noticed > the high half of register 0x240 was steadily increasing. > > Register 0x240 is called REG_FIFOPAGE_INFO_5. The driver writes the > number of pages allocated to the public queue into the low half. > The high half indicates the number of pages currently available. > The number of available pages was steadily increasing, beyond the > total number of pages: > > 00000240 072b070b 0003fa00 0003fe00 0003fa60 > 00000240 0737070b 0003fa00 0003fe00 0003fa60 > 00000240 073b070b 0003fa00 0003fe00 0003fa60 > 00000240 0741070b 0003fa00 0003fe00 0003fa60 > 00000240 0741070b 0003fa00 0003fe00 0003fa60 > 00000240 074f070b 0003fa00 0003fe00 0003fa60 > 00000240 075d070b 0003fa00 0003fe00 0003fa60 > > Normal values when the device is functional (and idle): > > 00000240 070b070b 0003fa00 0003fe00 0003fa60 > > When register 0x240 has strange values, register 0x210 > (REG_TXDMA_STATUS) has the value 5. Normally register 0x210 is 0. > > All this only happens in USB 3 mode. Everything is fine in USB 2 mode. I checked with internal USB team. The USB 3 mode can only work on 5GHz, because electrical interference between USB 3 clock and WiFi 2.4 GHz band. Could you check if it works on 5GHz? > > I tried to disable USB RX and TX aggregation, SUPPORTS_AMSDU_IN_AMPDU, > and TX_AMSDU. None of that helped. > > This problem happens also with this driver: > https://github.com/morrownr/88x2bu-20210702 > and with v5.13.1.1-1-g6f2541ef2.20240507_COEX20220812-18317b7b. By default, it only supports USB 2 mode. Have you changed the driver? > I see > the same strange values in register 0x240 in > /proc/net/rtl88x2bu/wlp3s0f3u4/mac_reg_dump. > > My test device is TP-Link Archer T3U Plus, with USB ID 2357:0138. > My system is Lenovo Ideapad 3 15ADA6 with AMD Athlon Gold 3150U CPU. > > Can this be fixed somehow? I saw the other drivers have some code in > rtw_sreset.c to power off and on the device when register 0x210 is > non-zero, but that seems suboptimal.
