Hi all, I am trying to debug a bug on an open source air navigation box for gliders called openvario <https://www.openvario.org/doku.php>. It is based on a cubieboard (A20) plus some additional serial connections and an optional sensor board for various flight related pressures.
System runs on kernel 5.18.5 generated using Yocto 4.0 kirkstone. The system tends to run for a couple of hours and then freezes/crashes. At the bottom of this post I have pasted a typical kernel debug output once these freezes happen. The crash always happens in the cpu_freq driver. If I set cpu frequency to a fixed frequency (setting min=max frequency) those crashed disappear. This seems to be a work around at the cost of fixing cpu speed. So it _seems_ the crash is caused by cpu_freq trying to change the cpu frequency (at least at some point in time). To be honest, I am rather clueless on how to go about finding the root of this issue, let along fixing it. So I thought, I'd ask around here whether this bug somehow looks familiar and may have been tackled (or even fixed) previously (didn't find anything, though, via the search function). In other words: I am thankful for any hint people may be able to give me to get nearer to a fix. thanks for any pointers Torsten [26996.004010] Unable to handle kernel paging request at virtual address 08d80050 [26996.011337] [08d80050] *pgd=00000000 [26996.014952] Internal error: Oops: 5 [#1 <https://github.com/Openvario/meta-openvario/pull/1>] SMP ARM [26996.019590] Modules linked in: [26996.022663] CPU: 1 PID: 95 Comm: sugov:0 Not tainted 5.18.5 #1 <https://github.com/Openvario/meta-openvario/pull/1> [26996.028509] Hardware name: Allwinner sun7i (A20) Family [26996.033738] PC is at ccu_div_recalc_rate+0x48/0x90 [26996.038555] LR is at ccu_mux_helper_apply_prediv+0x18/0x1c [26996.044054] pc : [] lr : [] psr: 600b0113 [26996.050326] sp : f09e5dc8 ip : 00000000 fp : c1938200 [26996.055554] r10: c1867440 r9 : 1f78a400 r8 : c1302d00 [26996.060781] r7 : 1312d000 r6 : 1f78a400 r5 : 00000002 r4 : 08d80084 [26996.067311] r3 : 00000000 r2 : ffffffff r1 : 00000001 r0 : 1f78a400 [26996.073843] Flags: nZCv IRQs on FIQs on Mode SVC_32 ISA ARM Segment none [26996.080985] Control: 10c5387d Table: 41ff006a DAC: 00000051 [26996.086733] Register r0 information: non-paged memory [26996.091799] Register r1 information: non-paged memory [26996.096858] Register r2 information: non-paged memory [26996.101915] Register r3 information: NULL pointer [26996.106627] Register r4 information: non-paged memory [26996.111688] Register r5 information: non-paged memory [26996.116746] Register r6 information: non-paged memory [26996.121805] Register r7 information: non-paged memory [26996.126863] Register r8 information: slab kmalloc-128 start c1302d00 pointer offset 0 size 128 [26996.135514] Register r9 information: non-paged memory [26996.140574] Register r10 information: slab task_struct start c1867440 pointer offset 0 [26996.148517] Register r11 information: slab kmalloc-128 start c1938200 pointer offset 0 size 128 [26996.157244] Register r12 information: NULL pointer [26996.162049] Process sugov:0 (pid: 95, stack limit = 0xf4bf205c) [26996.167985] Stack: (0xf09e5dc8 to 0xf09e6000) [26996.172361] 5dc0: c0d81584 c03db530 00000000 1f78a400 c1355700 c03d181c [26996.180547] 5de0: c1355600 c1355700 1f78a400 c03d34ec 00000000 c1355600 1f78a400 39387000 [26996.188733] 5e00: c1302d00 1f78a400 c1867440 c03d3554 00000000 c1302d00 016e3600 39387000 [26996.196917] 5e20: c1302d00 1f78a400 c1867440 c03d3554 c1355600 00000000 1f78a400 c1867440 [26996.205101] 5e40: c1302d00 1f78a400 c1867440 c03d39f0 1f78a400 00000000 ffffffff 1f78a400 [26996.213287] 5e60: c0d81bd0 df7bf617 c193a340 1f78a400 1f78a400 c1938300 ef7dc050 1f78a400 [26996.221474] 5e80: c1867440 c03d3c28 c18b3b00 c1938500 1f78a400 c1938300 ef7dc050 c06122a4 [26996.229659] 5ea0: c1938300 00000001 ffffffff df7bf617 c0d81bd0 c18b3b00 ef7dc050 1f78a400 [26996.237844] 5ec0: 00000007 c1867440 c1938500 c0db652c 00080e80 c0612674 00000000 c0db617c [26996.246030] 5ee0: 1f78a400 df7bf617 c1812800 c1812800 00000000 c0dfd944 000ea600 00000000 [26996.254214] 5f00: 00000002 c0617054 00000001 c1867440 00000000 00000000 f09e5f5c c1812800 [26996.262400] 5f20: 000ea600 00080e80 00000024 df7bf617 00000004 c184ba00 c184ba14 00000000 [26996.270585] 5f40: 00080e80 c184ba2c 00000001 c0a34650 00000000 c0159c98 00000000 c184ba28 [26996.278770] 5f60: c1867440 c0dea144 c184ba2c c0136954 c193a500 c1867440 c01368e0 c184ba28 [26996.286955] 5f80: c13c2100 f0891c44 00000000 c0138194 c193a500 c01380c4 00000000 00000000 [26996.295138] 5fa0: 00000000 00000000 00000000 c0100148 00000000 00000000 00000000 00000000 [26996.303321] 5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 [26996.311505] 5fe0: 00000000 00000000 00000000 00000000 00000013 00000000 00000000 00000000 [26996.319695] ccu_div_recalc_rate from clk_recalc+0x34/0x78 [26996.325215] clk_recalc from clk_change_rate+0xa4/0x29c [26996.330461] clk_change_rate from clk_change_rate+0x10c/0x29c [26996.336226] clk_change_rate from clk_change_rate+0x10c/0x29c [26996.341991] clk_change_rate from clk_core_set_rate_nolock+0x16c/0x234 [26996.348539] clk_core_set_rate_nolock from clk_set_rate+0x30/0x154 [26996.354741] clk_set_rate from _set_opp+0x268/0x550 [26996.359644] _set_opp from dev_pm_opp_set_rate+0xe8/0x20c [26996.365062] dev_pm_opp_set_rate from __cpufreq_driver_target+0x584/0x6e4 [26996.371876] __cpufreq_driver_target from sugov_work+0x48/0x54 [26996.377741] sugov_work from kthread_worker_fn+0x74/0x1a4 [26996.383167] kthread_worker_fn from kthread+0xd0/0xec [26996.388242] kthread from ret_from_fork+0x14/0x2c [26996.392967] Exception stack(0xf09e5fb0 to 0xf09e5ff8) [26996.398032] 5fa0: 00000000 00000000 00000000 00000000 [26996.406216] 5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000 [26996.414398] 5fe0: 00000000 00000000 00000000 00000000 00000013 00000000 [26996.421027] Code: e0055231 e244102c e3e02000 eb0001f3 (e5143034) -- You received this message because you are subscribed to the Google Groups 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