Kernel Panics with Realtek RTL8852AE

R

ricepu

Hello,

I have an RTL8852AE network adapter, and I'm using the RTW89 driver. I'm experiencing occasional kernel panics and crashes. I also added compat.linuxkpi.skb.mem_limit=1 to my loader.conf. I understand that this driver isn't fully supported yet, but I'm wondering if there's any way to avoid or at least minimize the frequency of these crashes.

Code: 
Oct  9 11:44:08 freebsd kernel: fault virtual address   = 0x0
Oct  9 11:44:08 freebsd kernel: fault code              = supervisor write data, page not present
Oct  9 11:44:08 freebsd kernel: instruction pointer     = 0x20:0xffffffff80dc7cf3
Oct  9 11:44:08 freebsd kernel: stack pointer           = 0x28:0xfffffe017b1d3cf0
Oct  9 11:44:08 freebsd kernel: frame pointer           = 0x28:0xfffffe017b1d3d00
Oct  9 11:44:08 freebsd kernel: code segment            = base 0x0, limit 0xfffff, type 0x1b
Oct  9 11:44:08 freebsd kernel:                         = DPL 0, pres 1, long 1, def32 0, gran 1
Oct  9 11:44:08 freebsd kernel: processor eflags        = interrupt enabled, resume, IOPL = 0
Oct  9 11:44:08 freebsd kernel: current process         = 0 (rtw89_tx_wq_16)
Oct  9 11:44:08 freebsd kernel: rdi: fffffe017d80d480 rsi: 0000000000000000 rdx: 0000000000000000
Oct  9 11:44:08 freebsd kernel: rcx: fffff801f04a9e00  r8: 000000000000007e  r9: 0000000000000080
Oct  9 11:44:08 freebsd kernel: rax: 0000000000000000 rbx: fffffe017d80d240 rbp: fffffe017b1d3d00
Oct  9 11:44:08 freebsd kernel: r10: 0000000000000000 r11: 00000000801a5ea7 r12: 0000000000000002
Oct  9 11:44:08 freebsd kernel: r13: fffffe017d80d540 r14: 0000000000000002 r15: fffffe017d80d480
Oct  9 11:44:08 freebsd kernel: trap number             = 12
Oct  9 11:44:08 freebsd kernel: panic: page fault
Oct  9 11:44:08 freebsd kernel: cpuid = 1
Oct  9 11:44:08 freebsd kernel: time = 1760028194
Oct  9 11:44:08 freebsd kernel: KDB: stack backtrace:
Oct  9 11:44:08 freebsd kernel: #0 0xffffffff80ba8f1d at kdb_backtrace+0x5d
Oct  9 11:44:08 freebsd kernel: #1 0xffffffff80b5aa11 at vpanic+0x161
Oct  9 11:44:08 freebsd kernel: #2 0xffffffff80b5a8a3 at panic+0x43
Oct  9 11:44:08 freebsd kernel: #3 0xffffffff8104dbfa at trap_pfault+0x3da
Oct  9 11:44:08 freebsd kernel: #4 0xffffffff81023db8 at calltrap+0x8
Oct  9 11:44:08 freebsd kernel: #5 0xffffffff83a06486 at rtw89_core_txq_work+0xa6
Oct  9 11:44:08 freebsd kernel: #6 0xffffffff80de7554 at linux_work_fn+0xe4
Oct  9 11:44:08 freebsd kernel: #7 0xffffffff80bbe4d2 at taskqueue_run_locked+0x182
Oct  9 11:44:08 freebsd kernel: #8 0xffffffff80bbf722 at taskqueue_thread_loop+0xc2
Oct  9 11:44:08 freebsd kernel: #9 0xffffffff80b13641 at fork_exit+0x81
Oct  9 11:44:08 freebsd kernel: #10 0xffffffff81024e1e at fork_trampoline+0xe
 
ricepu said:
I have an RTL8852AE
Click to expand...
Same here:
Rich (BB code): 
rtw890@pci0:3:0:0:    class=0x028000 rev=0x00 hdr=0x00 vendor=0x10ec device=0x8852 subvendor=0x17aa subdevice=0x4852
    vendor     = 'Realtek Semiconductor Co., Ltd.'
    device     = 'RTL8852AE 802.11ax PCIe Wireless Network Adapter

ricepu said:
I also added compat.linuxkpi.skb.mem_limit=1 to my loader.conf.
Click to expand...
You shouldn't need to set the variable manually, the rtw89 firmware package does this automatically:

Rich (BB code): 
 % pkg which /boot/loader.conf.d/rtw89.conf
/boot/loader.conf.d/rtw89.conf was installed by package wifi-firmware-rtw89-kmod-20241017.1403000_2

 % cat /boot/loader.conf.d/rtw89.conf
compat.linuxkpi.skb.mem_limit=1

ricepu said:
I'm wondering if there's any way to avoid or at least minimize the frequency of these crashes.
Click to expand...
There is nothing you can do to prevent crashes, except to try the latest version of the driver. 14.3-RELEASE is lagging behind the improved rtw89 version (and LinuxKPI , on which the driver depends) in CURRENT (aka main) and stable/15. On September 03, 2025, the developer of the driver (Bjoern A. Zeeb) has called for testing on the freebsd-wireless@ mailing list (you may want to subscribe there also to track the latest status of the driver, or report problems. The developer is answering to mails asap): "Please test iwlwifi/rtw88/rtw89 now"

If you are running 14.3-RELEASE, to test the driver, install [1] FreeBSD-15.0-ALPHA5 (the upcoming new -RELEASE in December, was 15-CURRENT/main, then, when the developer called for testing on 2025-09-03. 15 was branched off to stable/15 a few days later (20250905) from "main"). I myself hadn't the time to test, can't comment on the stability, but there is a user on the mailing list, reporting working fine on a earlier 15.0-PRERELEASE: Re: Please test iwlwifi/rtw88/rtw89 now:

If you're already running version 15, update to the latest version. If you continue to experience crashes, report it on the mailing list.

[1] On ZFS, create a new boot environment (bectl(8)), install there. UFS requires a new install/system upgrade, unless there is a spare partition or disk available to install on, if you don't want to touch the current installation.
 
It looks like it's performing significantly better in 15.0-ALPHA5. Scanning, connecting and switching between networks is noticeably faster. I haven't had any more kernel panics either, but they were quite random so I can't say for sure that they're fully resolved.

edit: I spoke too soon. I'm still seeing kernel panics, but apart from that the new driver does work a lot better.
 
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