cpufreq causes kernel stack overflow on IMX8MQ

[fourtrax1]

I have enabled the imx-cpufreq-dt module (CONFIG_ARM_IMX_CPUFREQ_DT) in the kernel (mainline, 5.10.197), which causes a stack overflow in the kernel at startup:

[ 3.425062] imx-cpufreq-dt imx-cpufreq-dt: cpu speed grade 2 mkt segment 2 supported-hw 0x4 0x4
[ 3.438041] Insufficient stack space to handle exception!
[ 3.438045] ESR: 0x96000047 -- DABT (current EL)
[ 3.438048] FAR: 0xffff8000131a7ff0
[ 3.438051] Task stack: [0xffff8000131a8000..0xffff8000131ac000]
[ 3.438053] IRQ stack: [0xffff800011200000..0xffff800011204000]
[ 3.438056] Overflow stack: [0xffff00003fdb3090..0xffff00003fdb4090]
[ 3.438058] CPU: 3 PID: 969 Comm: sugov:0 Not tainted 5.10.197 #1
[ 3.438061] Hardware name: Logic Board V2 (DT)
[ 3.438063] pstate: 00000085 (nzcv daIf -PAN -UAO -TCO BTYPE=--)
[ 3.438065] pc : unwind_frame+0x0/0x1b4
[ 3.438067] lr : walk_stackframe+0x40/0x54
[ 3.438069] sp : ffff8000131a8040
[ 3.438071] x29: ffff8000131a8040 x28: ffff000002b26568
[ 3.438079] x27: ffff000002b26c68 x26: ffff000002b26b00
[ 3.438084] x25: ffff000002b26500 x24: ffff000002b26c00
[ 3.438090] x23: 000000002faf0800 x22: ffff8000131a8070
[ 3.438094] x21: ffff80001000ea84 x20: ffff000002204380
[ 3.438100] x19: ffff8000131a8080 x18: 0000000000000000
[ 3.438104] x17: 0000000048e5cbee x16: 000000004f1627e2
[ 3.438110] x15: ffff000002c62720 x14: 0000000000000000
[ 3.438115] x13: 0000000100000000 x12: 0000000100000001
[ 3.438120] x11: 0000000000000005 x10: 0000000000000990
[ 3.438125] x9 : ffff80001046b7bc x8 : 00000000000f4240
[ 3.438130] x7 : 0000000000000000 x6 : ffff000002123028
[ 3.438135] x5 : 0000000000000003 x4 : 0000000000000000
[ 3.438140] x3 : ffff8000131a8070 x2 : 0000000000000002
[ 3.438145] x1 : ffff8000131a8080 x0 : ffff000002204380
[ 3.438151] Kernel panic - not syncing: kernel stack overflow
[ 3.438154] CPU: 3 PID: 969 Comm: sugov:0 Not tainted 5.10.197 #1
[ 3.438156] Hardware name: Logic Board V2 (DT)
[ 3.438158] Call trace:
[ 3.438160] dump_backtrace+0x0/0x1ec
[ 3.438162] show_stack+0x1c/0x24
[ 3.438164] dump_stack+0x108/0x158
[ 3.438165] panic+0x168/0x358
[ 3.438168] nmi_panic+0x50/0x70
[ 3.438170] handle_bad_stack+0x110/0x11c
[ 3.438172] __bad_stack+0x98/0x9c
[ 3.438174] unwind_frame+0x0/0x1b4
[ 3.438176] return_address+0x54/0x8c
[ 3.438177] trace_hardirqs_on+0x78/0xf8
[ 3.438180] __raw_spin_unlock_irqrestore+0x28/0x54
[ 3.438182] _raw_spin_unlock_irqrestore+0x14/0x1c
[ 3.438184] clk_enable_unlock+0x58/0x64
[ 3.438186] clk_core_enable_lock+0x34/0x44
[ 3.438189] clk_core_prepare_enable.isra.0+0x38/0x58
[ 3.438191] clk_change_rate+0xe4/0x2d8
[ 3.438193] clk_change_rate+0x2a0/0x2d8
[ 3.438195] clk_change_rate+0x2a0/0x2d8
[ 3.438197] clk_change_rate+0x2a0/0x2d8
[ 3.438199] clk_change_rate+0x2a0/0x2d8
[ 3.438202] clk_core_set_rate_nolock+0x164/0x194
[ 3.438204] clk_set_rate+0x40/0x70
[ 3.438206] clk_cpu_set_rate+0x40/0x78
[ 3.438208] clk_change_rate+0x198/0x2d8
[ 3.438210] clk_change_rate+0x2a0/0x2d8
[ 3.438212] clk_change_rate+0x2a0/0x2d8
[ 3.438214] clk_change_rate+0x2a0/0x2d8
[ 3.438216] clk_change_rate+0x2a0/0x2d8
[ 3.438218] clk_change_rate+0x2a0/0x2d8
[ 3.438220] clk_core_set_rate_nolock+0x164/0x194
[ 3.438223] clk_set_rate+0x40/0x70
[ 3.438225] clk_cpu_set_rate+0x40/0x78
[ 3.438227] clk_change_rate+0x198/0x2d8
[ 3.438229] clk_change_rate+0x2a0/0x2d8
[ 3.438231] clk_change_rate+0x2a0/0x2d8
[ 3.438233] clk_change_rate+0x2a0/0x2d8
[ 3.438235] clk_change_rate+0x2a0/0x2d8
[ 3.438237] clk_change_rate+0x2a0/0x2d8
[ 3.438240] clk_core_set_rate_nolock+0x164/0x194
[ 3.438241] clk_set_rate+0x40/0x70
[ 3.438243] clk_cpu_set_rate+0x40/0x78
[ 3.438246] clk_change_rate+0x198/0x2d8
[ 3.438248] clk_change_rate+0x2a0/0x2d8
[ 3.438250] clk_change_rate+0x2a0/0x2d8
[ 3.438252] clk_change_rate+0x2a0/0x2d8
[ 3.438254] clk_change_rate+0x2a0/0x2d8
[ 3.438256] clk_change_rate+0x2a0/0x2d8
[ 3.438259] clk_core_set_rate_nolock+0x164/0x194
[ 3.438260] clk_set_rate+0x40/0x70
[ 3.438263] clk_cpu_set_rate+0x40/0x78
[ 3.438264] clk_change_rate+0x198/0x2d8
[ 3.438267] clk_change_rate+0x2a0/0x2d8
[ 3.438269] clk_change_rate+0x2a0/0x2d8
[ 3.438271] clk_change_rate+0x2a0/0x2d8
[ 3.438273] clk_change_rate+0x2a0/0x2d8
[ 3.438275] clk_change_rate+0x2a0/0x2d8
[ 3.438277] clk_core_set_rate_nolock+0x164/0x194
[ 3.438279] clk_set_rate+0x40/0x70
[ 3.438281] clk_cpu_set_rate+0x40/0x78
[ 3.438283] clk_change_rate+0x198/0x2d8
[ 3.438286] clk_change_rate+0x2a0/0x2d8
[ 3.438288] clk_change_rate+0x2a0/0x2d8
[ 3.438290] clk_change_rate+0x2a0/0x2d8
[ 3.438292] clk_change_rate+0x2a0/0x2d8
[ 3.438294] clk_change_rate+0x2a0/0x2d8
[ 3.438296] clk_core_set_rate_nolock+0x164/0x194
[ 3.438298] clk_set_rate+0x40/0x70
[ 3.438300] clk_cpu_set_rate+0x40/0x78
[ 3.438303] clk_change_rate+0x198/0x2d8
[ 3.438305] clk_change_rate+0x2a0/0x2d8
[ 3.438307] clk_change_rate+0x2a0/0x2d8
[ 3.438309] clk_change_rate+0x2a0/0x2d8
[ 3.438311] clk_change_rate+0x2a0/0x2d8
[ 3.438313] clk_change_rate+0x2a0/0x2d8
[ 3.438315] clk_core_set_rate_nolock+0x164/0x194
[ 3.438317] clk_set_rate+0x40/0x70
[ 3.438319] clk_cpu_set_rate+0x40/0x78
[ 3.438321] clk_change_rate+0x198/0x2d8
[ 3.438324] clk_change_rate+0x2a0/0x2d8
[ 3.438326] clk_change_rate+0x2a0/0x2d8
[ 3.438328] clk_change_rate+0x2a0/0x2d8
[ 3.438330] clk_change_rate+0x2a0/0x2d8
[ 3.438332] clk_change_rate+0x2a0/0x2d8
[ 3.438334] clk_core_set_rate_nolock+0x164/0x194
[ 3.438336] clk_set_rate+0x40/0x70
[ 3.438338] clk_cpu_set_rate+0x40/0x78
[ 3.438340] clk_change_rate+0x198/0x2d8
[ 3.438342] clk_change_rate+0x2a0/0x2d8
[ 3.438344] clk_change_rate+0x2a0/0x2d8
[ 3.438346] clk_change_rate+0x2a0/0x2d8
[ 3.438348] clk_change_rate+0x2a0/0x2d8
[ 3.438350] clk_change_rate+0x2a0/0x2d8
[ 3.438353] clk_core_set_rate_nolock+0x164/0x194
[ 3.438355] clk_set_rate+0x40/0x70
[ 3.438357] clk_cpu_set_rate+0x40/0x78
[ 3.438359] clk_change_rate+0x198/0x2d8
[ 3.438361] clk_change_rate+0x2a0/0x2d8
[ 3.438363] clk_change_rate+0x2a0/0x2d8
[ 3.438365] clk_change_rate+0x2a0/0x2d8
[ 3.438367] clk_change_rate+0x2a0/0x2d8
[ 3.438370] clk_change_rate+0x2a0/0x2d8
[ 3.438372] clk_core_set_rate_nolock+0x164/0x194
[ 3.438374] clk_set_rate+0x40/0x70
[ 3.438376] clk_cpu_set_rate+0x40/0x78
[ 3.438378] clk_change_rate+0x198/0x2d8
[ 3.438380] clk_change_rate+0x2a0/0x2d8
[ 3.438382] clk_change_rate+0x2a0/0x2d8
[ 3.438384] clk_change_rate+0x2a0/0x2d8
[ 3.438387] clk_change_rate+0x2a0/0x2d8
[ 3.438389] clk_change_rate+0x2a0/0x2d8
[ 3.438391] clk_core_set_rate_nolock+0x164/0x194
[ 3.438393] clk_set_rate+0x40/0x70
[ 3.438395] clk_cpu_set_rate+0x40/0x78
[ 3.438397] clk_change_rate+0x198/0x2d8
[ 3.438399] clk_change_rate+0x2a0/0x2d8
[ 3.438401] clk_change_rate+0x2a0/0x2d8
[ 3.438404] clk_change_rate+0x2a0/0x2d8
[ 3.438405] clk_change_rate+0x2a0/0x2d8
[ 3.438408] clk_change_rate+0x2a0/0x2d8
[ 3.438410] clk_core_set_rate_nolock+0x164/0x194
[ 3.438412] clk_set_rate+0x40/0x70
[ 3.438414] clk_cpu_set_rate+0x40/0x78
[ 3.438416] clk_change_rate+0x198/0x2d8
[ 3.438418] clk_change_rate+0x2a0/0x2d8
[ 3.438420] clk_change_rate+0x2a0/0x2d8
[ 3.438422] clk_change_rate+0x2a0/0x2d8
[ 3.438424] clk_change_rate+0x2a0/0x2d8
[ 3.438426] clk_change_rate+0x2a0/0x2d8
[ 3.438429] clk_core_set_rate_nolock+0x164/0x194
[ 3.438431] clk_set_rate+0x40/0x70
[ 3.438433] clk_cpu_set_rate+0x40/0x78
[ 3.438435] clk_change_rate+0x198/0x2d8
[ 3.438437] clk_change_rate+0x2a0/0x2d8
[ 3.438439] clk_change_rate+0x2a0/0x2d8
[ 3.438441] clk_change_rate+0x2a0/0x2d8
[ 3.438443] clk_change_rate+0x2a0/0x2d8
[ 3.438445] clk_change_rate+0x2a0/0x2d8
[ 3.438447] clk_core_set_rate_nolock+0x164/0x194
[ 3.438450] clk_set_rate+0x40/0x70
[ 3.438452] clk_cpu_set_rate+0x40/0x78
[ 3.438454] clk_change_rate+0x198/0x2d8
[ 3.438456] clk_change_rate+0x2a0/0x2d8
[ 3.438458] clk_change_rate+0x2a0/0x2d8
[ 3.438460] clk_change_rate+0x2a0/0x2d8
[ 3.438462] clk_change_rate+0x2a0/0x2d8
[ 3.438464] clk_change_rate+0x2a0/0x2d8
[ 3.438466] clk_core_set_rate_nolock+0x164/0x194
[ 3.438468] clk_set_rate+0x40/0x70
[ 3.438471] clk_cpu_set_rate+0x40/0x78
[ 3.438473] clk_change_rate+0x198/0x2d8
[ 3.438475] clk_change_rate+0x2a0/0x2d8
[ 3.438477] clk_change_rate+0x2a0/0x2d8
[ 3.438479] clk_change_rate+0x2a0/0x2d8
[ 3.438481] clk_change_rate+0x2a0/0x2d8
[ 3.438483] clk_change_rate+0x2a0/0x2d8
[ 3.438485] clk_core_set_rate_nolock+0x164/0x194
[ 3.438488] clk_set_rate+0x40/0x70
[ 3.438490] clk_cpu_set_rate+0x40/0x78
[ 3.438492] clk_change_rate+0x198/0x2d8
[ 3.438494] clk_change_rate+0x2a0/0x2d8
[ 3.438496] clk_change_rate+0x2a0/0x2d8
[ 3.438498] clk_change_rate+0x2a0/0x2d8
[ 3.438500] clk_change_rate+0x2a0/0x2d8
[ 3.438502] clk_change_rate+0x2a0/0x2d8
[ 3.438505] clk_core_set_rate_nolock+0x164/0x194
[ 3.438507] clk_set_rate+0x40/0x70
[ 3.438509] clk_cpu_set_rate+0x40/0x78
[ 3.438511] clk_change_rate+0x198/0x2d8
[ 3.438513] clk_change_rate+0x2a0/0x2d8
[ 3.438515] clk_change_rate+0x2a0/0x2d8
[ 3.438517] clk_change_rate+0x2a0/0x2d8
[ 3.438519] clk_change_rate+0x2a0/0x2d8
[ 3.438521] clk_change_rate+0x2a0/0x2d8
[ 3.438523] clk_core_set_rate_nolock+0x164/0x194
[ 3.438525] clk_set_rate+0x40/0x70
[ 3.438528] clk_cpu_set_rate+0x40/0x78
[ 3.438530] clk_change_rate+0x198/0x2d8
[ 3.438532] clk_change_rate+0x2a0/0x2d8
[ 3.438534] clk_change_rate+0x2a0/0x2d8
[ 3.438536] clk_change_rate+0x2a0/0x2d8
[ 3.438538] clk_change_rate+0x2a0/0x2d8
[ 3.438540] clk_change_rate+0x2a0/0x2d8
[ 3.438542] clk_core_set_rate_nolock+0x164/0x194
[ 3.438544] clk_set_rate+0x40/0x70
[ 3.438546] clk_cpu_set_rate+0x40/0x78
[ 3.438548] clk_change_rate+0x198/0x2d8
[ 3.438550] clk_change_rate+0x2a0/0x2d8
[ 3.438552] clk_change_rate+0x2a0/0x2d8
[ 3.438555] clk_change_rate+0x2a0/0x2d8
[ 3.438557] clk_change_rate+0x2a0/0x2d8
[ 3.438559] clk_change_rate+0x2a0/0x2d8
[ 3.438561] clk_core_set_rate_nolock+0x164/0x194
[ 3.438563] clk_set_rate+0x40/0x70
[ 3.438565] clk_cpu_set_rate+0x40/0x78
[ 3.438567] clk_change_rate+0x198/0x2d8
[ 3.438569] clk_change_rate+0x2a0/0x2d8
[ 3.438571] clk_change_rate+0x2a0/0x2d8
[ 3.438573] clk_change_rate+0x2a0/0x2d8
[ 3.438576] clk_change_rate+0x2a0/0x2d8
[ 3.438578] clk_change_rate+0x2a0/0x2d8
[ 3.438580] clk_core_set_rate_nolock+0x164/0x194
[ 3.438582] clk_set_rate+0x40/0x70
[ 3.438584] clk_cpu_set_rate+0x40/0x78
[ 3.438586] clk_change_rate+0x198/0x2d8
[ 3.438588] clk_change_rate+0x2a0/0x2d8
[ 3.438590] clk_change_rate+0x2a0/0x2d8
[ 3.438592] clk_change_rate+0x2a0/0x2d8
[ 3.438594] clk_change_rate+0x2a0/0x2d8
[ 3.438596] clk_change_rate+0x2a0/0x2d8
[ 3.438599] clk_core_set_rate_nolock+0x164/0x194
[ 3.438601] clk_set_rate+0x40/0x70
[ 3.438603] clk_cpu_set_rate+0x40/0x78
[ 3.438605] clk_change_rate+0x198/0x2d8
[ 3.438607] clk_change_rate+0x2a0/0x2d8
[ 3.438609] clk_change_rate+0x2a0/0x2d8
[ 3.438612] clk_change_rate+0x2a0/0x2d8
[ 3.438613] clk_change_rate+0x2a0/0x2d8
[ 3.438615] clk_change_rate+0x2a0/0x2d8
[ 3.438618] clk_core_set_rate_nolock+0x164/0x194
[ 3.438620] clk_set_rate+0x40/0x70
[ 3.438622] clk_cpu_set_rate+0x40/0x78
[ 3.438624] clk_change_rate+0x198/0x2d8
[ 3.438626] clk_core_set_rate_nolock+0x164/0x194
[ 3.438628] clk_set_rate+0x40/0x70
[ 3.438631] _generic_set_opp_clk_only+0x1c/0x54
[ 3.438633] dev_pm_opp_set_rate+0x448/0x4dc
[ 3.438635] set_target+0x34/0x3c
[ 3.438637] __cpufreq_driver_target+0x228/0x300
[ 3.438639] sugov_work+0x58/0x70
[ 3.438641] kthread_worker_fn+0xa0/0xe4
[ 3.438643] kthread
[ 3.438646] Lost 1 message(s)!
[ 3.438667] SMP: stopping secondary CPUs
[ 3.438669] Kernel Offset: disabled
[ 3.438671] CPU features: 0x00040002,2000200c
[ 3.438673] Memory Limit: none

I have stepped through clk_change_rate using gdb and it is trying to transition from 800Mhz to 1.3Ghz but not sure why it keeps calling itself until the stack runs out.

Any ideas what might be causing this behaviour?

Many thanks in advance

[fourtrax1]

Hi,

thanks a lot for your reply. I tested 6.6 kernel but it shows the same behaviour unfortunately, we have to use mainline.

Kind regards

[Bio_TICFSL]

Hello,

The  CONFIG_ARM_IMX_CPUFREQ_DT is unstable un 5.10 kernel, better try on 6.6.:

https://www.nxp.com/design/design-center/software/embedded-software/i-mx-software/embedded-linux-for...

Regards