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

[Parth Panchoil]

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
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