Illegal Instruction Warning in riscv_v_first_use_handler

[mrbilandi]

Hello

When I am attempting to offload an operation to the Ara (in Cheshire+Ara), the kernel logs a warning about an illegal instruction exception repeatedly in the riscv_v_first_use_handler.

This is the Kernel Log:

[ 749.660683] WARNING: CPU: 0 PID: 93 at arch/riscv/kernel/vector.c:158 riscv_v_first_use_handler+0x16a/0x16e
[ 749.663520] Modules linked in:
[ 749.664911] CPU: 0 PID: 93 Comm: hal_cpu_server_ Tainted: G W 6.5.0 #3
[ 749.666311] Hardware name: eth,cheshire (DT)
[ 749.667110] epc : riscv_v_first_use_handler+0x16a/0x16e
[ 749.669199] ra : riscv_v_first_use_handler+0x1c/0x16e
[ 749.671176] epc : ffffffff800064ac ra : ffffffff8000635e sp : ffffffc80015be90
[ 749.672374] gp : ffffffff818bb618 tp : ffffffd801e2a700 t0 : ffffffff804f7170
[ 749.673539] t1 : ffffffff814001f8 t2 : ffffffff81400278 s0 : ffffffc80015bec0
[ 749.674610] s1 : ffffffc80015bee0 a0 : 000000000020112d a1 : 0000000000000003
[ 749.675714] a2 : 000000005208a457 a3 : 0000000000000057 a4 : 0000000000000057
[ 749.676397] a5 : ffffffd801fc0000 a6 : 0000003facf59080 a7 : 0000003facf59080
[ 749.676759] s2 : 000000005208a457 s3 : 0000003facce3ea0 s4 : 0000000000000002
[ 749.677110] s5 : 0000003fad522ea0 s6 : 0000000000005a00 s7 : 0000000000006000
[ 749.677477] s8 : 0000000000005d00 s9 : 0000000000006300 s10: 0000000000006600
[ 749.678460] s11: 0000000000006900 t3 : 0000003facf59080 t4 : 0000003facf59080
[ 749.679527] t5 : 0000003facf59080 t6 : 0000000000000000
[ 749.680553] status: 0000000200000120 badaddr: 0000000000009002 cause: 0000000000000003
[ 749.681675] [] riscv_v_first_use_handler+0x16a/0x16e
[ 749.683897] [] do_trap_insn_illegal+0x28/0xe8
[ 749.686023] [] ret_from_exception+0x0/0x64

Could this issue be related to the number of elements used during vectorization? If so, is there a limit or configuration needed for Ara?
Are there diagnostics or debugging steps I can follow to identify the root cause?

Thanks for your attention