wifi: ath12k: start-up crash with WCN7850 hw2.0 on TI AM69-SK board

Fri Jan 24 02:02:54 PST 2025

I appreciate your response, Baochen.

I have been working on enabling mainline kernel support on my TI AM69-
SK board to test the mainline ath12k driver on my system.

Using the mainline kernel repository for the ath drivers [1], I made
the following observation: 
While the exact crash observed earlier is no longer present, the system
hangs upon loading the ath12k mainline driver, displaying the messages
below.

root at am69-sk:~# modprobe ath12k debug_mask=0xffffffff
[ 1121.996554] ath12k_pci 0000:01:00.0: BAR 0 [mem 0x4410200000-
0x44103fffff 64bit]: assigned
[ 1122.004884] ath12k_pci 0000:01:00.0: enabling device (0000 -> 0002)
[ 1122.011818] ath12k_pci 0000:01:00.0: MSI vectors: 16
[ 1122.016798] ath12k_pci 0000:01:00.0: Hardware name: wcn7850 hw2.0
[ 1122.040183] NET: Registered PF_QIPCRTR protocol family

root at am69-sk:~# uname -a
Linux am69-sk 6.13.0-rc7-wt-ath-ge7ef944b3e2c-dirty #2 SMP PREEMPT Wed
Jan 22 16:55:17 CET 2025 aarch64 GNU/Linux

root at am69-sk:~# lspci
0000:00:00.0 PCI bridge: Texas Instruments Device b012
0000:01:00.0 Network controller: Qualcomm Technologies, Inc WCN785x Wi-
Fi 7(802.11be) 320MHz 2x2 [FastConnect 7800] (rev 01)
0001:00:00.0 PCI bridge: Texas Instruments Device b012
0002:00:00.0 PCI bridge: Texas Instruments Device b012

Do you have any insights into what might still be missing or incorrect
in my setup?

Regards,
Parth P

On Wed, 2025-01-22 at 15:20 +0800, Baochen Qiang wrote:
> 
> 
> On 1/21/2025 10:19 PM, Parth Panchoil wrote:
> > Hi All,
> > 
> > I am performing tests on the SX-PCEBE Wi-Fi module, which utilizes
> > the
> > ATH12k driver, on the Texas Instruments AM69-SK board.
> > The board is running the TI Linux Kernel from the ti-linux-6.6.y
> 
> 6.6 is too old, and besides we don;t support customer kernel.
> 
> Could you try latest ath tree [1] or the mainline tree [2]?
> 
> [1] https://git.kernel.org/pub/scm/linux/kernel/git/ath/ath.git/
> [2]
> https://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git/
> 
> If the issue is still seen, please enable verbose ath12k log using
> below command and help
> collect dmesg logs:
> 
>         sudo modprobe ath12k debug_mask=0xffffffff
> 
> One more thing, the open-WRT patch is overkill, can you narrow down
> to find which line of
> code in ath12k_pci_enable_ltssm() is causing this issue?
> 
> 
> > branch. During testing, I observed a kernel crash from the ATH12k
> > driver as soon as the probe is called. The crash log is as follows:
> > 
> > [    9.492631] Kernel panic - not syncing: Asynchronous SError
> > Interrupt
> > [    9.492634] CPU: 7 PID: 222 Comm: (udev-worker) Not tainted
> > 6.6.58-
> > 01497-ga7758da17c28-dirty #1
> > [    9.492638] Hardware name: Texas Instruments AM69 SK (DT)
> > [    9.492640] Call trace:
> > [    9.492642]  dump_backtrace+0x94/0xec
> > [    9.492658]  show_stack+0x18/0x24
> > [    9.492662]  dump_stack_lvl+0x48/0x60
> > [    9.492669]  dump_stack+0x18/0x24
> > [    9.492672]  panic+0x320/0x378
> > [    9.492677]  nmi_panic+0x8c/0x90
> > [    9.492681]  arm64_serror_panic+0x6c/0x78
> > [    9.492686]  do_serror+0x3c/0x78
> > [    9.492692]  el1h_64_error_handler+0x34/0x4c
> > [    9.492697]  el1h_64_error+0x64/0x68
> > [    9.492700]  ath12k_pci_read32+0x1bc/0x1e8 [ath12k]
> > [    9.492725]  ath12k_pci_power_up+0xdc/0x340 [ath12k]
> > [    9.492747]  ath12k_core_init+0x2c/0xa8 [ath12k]
> > [    9.492769]  ath12k_pci_probe+0x698/0x908 [ath12k]
> > [    9.492791]  pci_device_probe+0xa8/0x16c
> > [    9.492800]  really_probe+0x110/0x27c
> > [    9.492805]  __driver_probe_device+0x78/0x12c
> > [    9.492808]  driver_probe_device+0x3c/0x118
> > [    9.492810]  __driver_attach+0x74/0x124
> > [    9.492813]  bus_for_each_dev+0x78/0xd8
> > [    9.492819]  driver_attach+0x24/0x30
> > [    9.492824]  bus_add_driver+0xe4/0x208
> > [    9.492828]  driver_register+0x60/0x128
> > [    9.492831]  __pci_register_driver+0x44/0x50
> > [    9.492835]  ath12k_pci_init+0x2c/0x6c [ath12k]
> > [    9.492858]  do_one_initcall+0x70/0x1b4
> > [    9.492861]  do_init_module+0x58/0x1e4
> > [    9.492867]  load_module+0x19bc/0x1a8c
> > [    9.492869]  init_module_from_file+0x88/0xc4
> > [    9.492873]  __arm64_sys_finit_module+0x1c0/0x2ac
> > [    9.492877]  invoke_syscall+0x44/0x108
> > [    9.492882]  el0_svc_common.constprop.0+0xc0/0xe0
> > [    9.492885]  do_el0_svc+0x1c/0x28
> > [    9.492889]  el0_svc+0x2c/0x84
> > [    9.492892]  el0t_64_sync_handler+0xc0/0xc4
> > [    9.492895]  el0t_64_sync+0x190/0x194
> > [    9.492899] SMP: stopping secondary CPUs
> > [    9.492908] Kernel Offset: disabled
> > [    9.492909] CPU features: 0x0,80000200,28020000,1000420b
> > [    9.492913] Memory Limit: none
> > 
> > Upon searching online, I found the OpenWRT patch that appears to
> > address a similar issue: OpenWRT Patch: Prevent LTSSM Startup
> > Crash.
> > https://git.openwrt.org/?p=openwrt/openwrt.git;a=blob;f=package/kernel/mac80211/patches/ath12k/100-ath12k-prevent-ltssm-startup-crash.patch;h=cd85a0f6aa2652d62bfbea04e9bcca3bcf831b7f;hb=935b2b7dcef61b2893ed5dff307dd8f8a1156899
> > With the above patch applied, I do not see the crash anymore.
> > 
> > Could anyone confirm if this issue has been reported before/known
> > bug
> > or provide any insights? 
> > Any additional information or suggestions would be greatly
> > appreciated.
> > 
> > Details about the test setup,
> > TI-AM69-SK board:
> > https://www.ti.com/tool/SK-AM69?keyMatch=am69%20sk&tisearch=universal_search
> > Silex WiFi card SX-PCEBE:
> > https://www.silextechnology.com/connectivity-solutions/embedded-wireless/sx-pcebe
> > TI Linux Repo:
> > https://git.ti.com/cgit/ti-linux-kernel/ti-linux-kernel/?h=ti-linux-6.6.y
> > 
> > Thank you.
> > 
> > Regards,
> > Parth P
> > 
> 
> 