Hi Tp-link,

I just bought a TL-WN722N usb wifi dongle and it can work well on my device with Linux.

However, if my device run with Linux RT patch, the dongle will trigger a kernel panic as below.

We want to know if it's not suitable for RT patch? Is it possible to fix this?

Or do you have any other usb wifi dongle can run as well with Linux RT patch?

oot@am65xx-evm:~# [   95.288419] R8188EU: assoc success
[   95.290692] IPv6: ADDRCONF(NETDEV_CHANGE): wlan0: link becomes ready
[   95.375461] R8188EU: sta recv deauth reason code(3) sta:00:fe:c8:28:12:f0
[   95.375905] R8188EU: sta recv deauth reason code(7) sta:00:fe:c8:28:12:f0
[   95.378284] Unable to handle kernel paging request at virtual address ffff80001256e054
[   95.399799] printk: console [ttyS2]: printing thread stopped
[   95.406208] Mem abort info:
[   95.409048]   ESR = 0x96000021
[   95.412113]   EC = 0x25: DABT (current EL), IL = 32 bits
[   95.417425]   SET = 0, FnV = 0
[   95.420479]   EA = 0, S1PTW = 0
[   95.423620] Data abort info:
[   95.426491]   ISV = 0, ISS = 0x00000021
[   95.430324]   CM = 0, WnR = 0
[   95.433292] swapper pgtable: 4k pages, 48-bit VAs, pgdp=0000000082e93000
[   95.439991] [ffff80001256e054] pgd=00000008fffff003, p4d=00000008fffff003, pud=00000008ffffe003, pmd=0000000881750003, pte=00680008837bc703
[   95.452514] Internal error: Oops: 96000021 [#1] PREEMPT_RT SMP
[   95.458338] Modules linked in: r8188eu(C) lib80211 cfg80211 bluetooth ecdh_generic ecc rfkill xhci_plat_hcd xhci_hcd usbcore rpmsg_char ti_am335x_adc kfifo_buf dwc3 omap_rng rng_core irq_pruss_intc udc_core roles usb_common crct10dif_ce icssg_prueth pru_rproc icss_iep phy_can_transceiver ti_k3_r5_remoteproc virtio_rpmsg_bus m_can_platform m_can can_dev ti_am335x_tscadc ti_cal videobuf2_dma_contig v4l2_fwnode videobuf2_memops videobuf2_v4l2 videobuf2_common pruss sa2ul dwc3_keystone sha512_generic phy_omap_usb2 authenc sch_fq_codel ipv6
[   95.505830] CPU: 0 PID: 1325 Comm: RTW_CMD_THREAD Tainted: G         C O      5.10.100-rt62-g204ec708dc #24
[   95.515557] Hardware name: Texas Instruments AM654 Base Board (DT)
[   95.521724] pstate: 40000005 (nZcv daif -PAN -UAO -TCO BTYPE=--)
[   95.527721] pc : rt_spin_unlock+0xa8/0x130
[   95.531823] lr : rtw_free_xmitframe_queue+0x38/0x90 [r8188eu]
[   95.537665] sp : ffff8000130e3c40
[   95.540970] x29: ffff8000130e3c40 x28: ffff800008dd9308
[   95.546276] x27: ffff800011a77000 x26: ffff800011a770a0
[   95.551580] x25: ffff800008dec000 x24: ffff800011a77008
[   95.556885] x23: ffff80001256dd6c x22: ffff80001256e03c
[   95.562190] x21: ffff800011a785e8 x20: ffff80001256e02c
[   95.567496] x19: ffff800011a785e8 x18: 000000000000000e
[   95.572800] x17: 0000000000000001 x16: 0000000000000019
[   95.578104] x15: 0000058ddd7e1f52 x14: 0000000000000267
[   95.583409] x13: 0000000000000000 x12: 0000000000000001
[   95.588713] x11: 0000000000000433 x10: 0000000000000a50
[   95.594018] x9 : ffff8000130e3950 x8 : ffff00087f784ec0
[   95.599322] x7 : ffff000000000000 x6 : 00000000000015e8
[   95.604626] x5 : ffff80001256e054 x4 : 0000000000000800
[   95.609931] x3 : ffff80001256e03c x2 : ffff000804e749c0
[   95.615235] x1 : 0000000000000000 x0 : ffff80001256e03c
[   95.620540] Call trace:
[   95.622980]  rt_spin_unlock+0xa8/0x130
[   95.626724]  rtw_free_xmitframe_queue+0x38/0x90 [r8188eu]
[   95.632192]  rtw_free_stainfo+0x58/0x3f0 [r8188eu]
[   95.637054]  rtw_free_assoc_resources_locked+0x7c/0x228 [r8188eu]
[   95.643217]  rtw_free_assoc_resources+0x38/0x60 [r8188eu]
[   95.648687]  rtw_stadel_event_callback+0x188/0x3a0 [r8188eu]
[   95.654415]  mlme_evt_hdl+0x5c/0x128 [r8188eu]
[   95.658929]  rtw_cmd_thread+0x1e4/0x310 [r8188eu]
[   95.663705]  kthread+0x174/0x198
[   95.666931]  ret_from_fork+0x10/0x34
[   95.670512] Code: c8047ca2 35ffff84 17ffff30 f98000b1 (c85ffca0)
[   95.676600] ---[ end trace 0000000000000002 ]---
[   95.681362] Kernel panic - not syncing:
[   95.685186] Oops: Fatal exception in interrupt
[   95.685303] SMP: stopping secondary CPUs
[   95.693677] Kernel Offset: disabled
[   95.697155] CPU features: 0x0040002,2000200c
[   95.701415] Memory Limit: none
[   95.704464] ---[ end Kernel panic - not syncing: Oops: Fatal exception in interrupt ]---

Thanks.