wifi: ath12k: start-up crash with WCN7850 hw2.0 on TI AM69-SK board
Parth Panchoil
parth105105 at gmail.com
Mon Jan 27 06:01:25 PST 2025
Hi,
I am currently debugging the ath12k_pci_enable_ltssm start up crash/bug
with the mainline kernel on my system and would like to share my
observations so far:
The ath12k mainline driver gets stuck at this specific line:
https://github.com/torvalds/linux/blob/9c5968db9e625019a0ee5226c7eebef5519d366a/drivers/net/wireless/ath/ath12k/pci.c#L295
in the ath12k_pci_enable_ltssm which attempts to read
GCC_GCC_PCIE_HOT_RST, particularly
https://github.com/torvalds/linux/blob/9c5968db9e625019a0ee5226c7eebef5519d366a/drivers/net/wireless/ath/ath12k/pci.c#L1209
Interestingly, within the same function, the line val =
ath12k_pci_read32(ab, PCIE_PCIE_PARF_LTSSM) successfully reads the
expected value 0x111 for PCIE_PCIE_PARF_LTSSM.
I am continuing to debug from my end, although my understanding of the
ath12k driver is limited. Any leads, suggestions, or hints to help
resolve this issue would be greatly appreciated.
Thank you.
Regards,
Parth P
On Fri, 2025-01-24 at 10:02 +0000, Parth Pancholi wrote:
> 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
> > >
> >
> >
>
>
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