Other Parts Discussed in Thread: AM5718
Hello,
we observes Sitara lock down issues from time to time (very low occurrence): Linux never finishes the boot sequence and seems to loop endless during UART3 initialization.
Project use Sitara UART3 at 3 110 400 bits/s, and receive 300 bytes of UART3 data every 90ms during Linux boot.
Please see emulator stack screenshot when this lock down appears.
And a Linux kernel log (not the same issue time than stack screenshot).
Any idea about it?
Thanks for your help,
Benoît
[ 42.261953] INFO: rcu_preempt self-detected stall on CPU [ 42.267099] 0-...: (2100 ticks this GP) idle=ff5/140000000000002/0 softirq=0/0 fqs=0 [ 42.274734] (t=2100 jiffies g=121 c=120 q=5) [ 42.279035] rcu_preempt kthread starved for 2100 jiffies! g121 c120 f0x0 s3 ->state=0x1 [ 42.286755] Task dump for CPU 0: [ 42.289869] main_VAHM R running 0 390 1 0x00000002 [ 42.296019] Backtrace: [ 42.298408] [<c0013550>] (dump_backtrace) from [<c001374c>] (show_stack+0x18/0x1c) [ 42.305708] r7:c0a9a884 r6:80080193 r5:00000001 r4:d8396400 [ 42.311220] [<c0013734>] (show_stack) from [<c005684c>] (sched_show_task+0xbc/0x110) [ 42.318694] [<c0056790>] (sched_show_task) from [<c0058860>] (dump_cpu_task+0x40/0x48) [ 42.326328] r5:c0aaa600 r4:00000000 [ 42.329805] [<c0058820>] (dump_cpu_task) from [<c007cad4>] (rcu_dump_cpu_stacks+0x94/0xd0) [ 42.337775] r5:c0aaa600 r4:00000001 [ 42.341247] [<c007ca40>] (rcu_dump_cpu_stacks) from [<c0080b88>] (rcu_check_callbacks+0x520/0x8d4) [ 42.349886] r9:dfd6d1c0 r8:c0aaa600 r7:00000005 r6:c0a9a140 r5:1f2d6000 r4:c0a971c0 [ 42.357418] [<c0080668>] (rcu_check_callbacks) from [<c0083c38>] (update_process_times+0x48/0x6c) [ 42.365972] r10:c009401c r9:00000001 r8:dfd69c0c r7:00000009 r6:00000000 r5:d8396400 [ 42.373580] r4:ffffe000 [ 42.376042] [<c0083bf0>] (update_process_times) from [<c0094018>] (tick_sched_handle+0x50/0x54) [ 42.384429] r7:00000009 r6:d6e47e18 r5:d7045b48 r4:dfd69e88 [ 42.389937] [<c0093fc8>] (tick_sched_handle) from [<c0094078>] (tick_sched_timer+0x5c/0xa0) [ 42.397998] [<c009401c>] (tick_sched_timer) from [<c00846b0>] (__hrtimer_run_queues+0x11c/0x1ac) [ 42.406469] r7:00000000 r6:dfd69c00 r5:dfd69e88 r4:dfd69bc0 [ 42.411976] [<c0084594>] (__hrtimer_run_queues) from [<c0084ed4>] (hrtimer_interrupt+0xbc/0x208) [ 42.420446] r10:dfd69c60 r9:dfd69ce0 r8:dfd69ca0 r7:dfd69bd8 r6:ffffffff r5:00000003 [ 42.428051] r4:dfd69bc0 [ 42.430515] [<c0084e18>] (hrtimer_interrupt) from [<c037a7e4>] (arch_timer_handler_virt+0x38/0x40) [ 42.439152] r10:d7045b48 r9:ddc06000 r8:ddc3af00 r7:ddc04e40 r6:00000013 r5:c0ab0bcc [ 42.446759] r4:dfd6f840 [ 42.449220] [<c037a7ac>] (arch_timer_handler_virt) from [<c0076c64>] (handle_percpu_devid_irq+0x90/0xa8) [ 42.458370] [<c0076bd4>] (handle_percpu_devid_irq) from [<c0072634>] (generic_handle_irq+0x2c/0x3c) [ 42.467091] r9:ddc06000 r8:00000001 r7:d7045c68 r6:00000013 r5:00000000 r4:c0a941e4 [ 42.474621] [<c0072608>] (generic_handle_irq) from [<c007292c>] (__handle_domain_irq+0x84/0xf4) [ 42.483015] [<c00728a8>] (__handle_domain_irq) from [<c0009538>] (gic_handle_irq+0x50/0x94) [ 42.491068] r10:d7045c68 r9:fa213000 r8:fa212000 r7:d7045b48 r6:fa21200c r5:c0a9aac8 [ 42.498674] r4:c0ab0bc8 r3:d7045b48 [ 42.502147] [<c00094e8>] (gic_handle_irq) from [<c0014294>] (__irq_svc+0x54/0xa4) [ 42.509364] Exception stack(0xd7045b48 to 0xd7045b90) [ 42.514240] 5b40: 00000000 c053a6a4 c0acbb40 00000000 00000002 ffffe000 [ 42.522131] 5b60: 00000013 00000000 00000001 ddc06000 d7045c68 d7045bf4 d7045b88 d7045b98 [ 42.530018] 5b80: c025c938 c003462c 20080113 ffffffff [ 42.534889] r9:ddc06000 r8:00000001 r7:d7045b7c r6:ffffffff r5:20080113 r4:c003462c [ 42.542421] [<c0034584>] (__do_softirq) from [<c0034ef8>] (irq_exit+0xc8/0x104) [ 42.549469] r10:d7045c68 r9:ddc06000 r8:00000001 r7:00000000 r6:00000013 r5:00000000 [ 42.557071] r4:c0a941e4 [ 42.559534] [<c0034e30>] (irq_exit) from [<c0072930>] (__handle_domain_irq+0x88/0xf4) [ 42.567084] r5:00000000 r4:c0a941e4 [ 42.570558] [<c00728a8>] (__handle_domain_irq) from [<c0009538>] (gic_handle_irq+0x50/0x94) [ 42.578610] r10:00000001 r9:fa213000 r8:fa212000 r7:d7045c68 r6:fa21200c r5:c0a9aac8 [ 42.586214] r4:c0ab0bc8 r3:d7045c68 [ 42.589687] [<c00094e8>] (gic_handle_irq) from [<c0014294>] (__irq_svc+0x54/0xa4) [ 42.596903] Exception stack(0xd7045c68 to 0xd7045cb0) [ 42.601778] 5c60: c0aede34 00000003 00000000 00000005 c0aede34 d82886b8 [ 42.609669] 5c80: ddf2b610 00000013 002dc6c0 000a9053 00000001 d7045cc4 d7045cc8 d7045cb8 [ 42.617556] 5ca0: c02d6544 c045fdfc a0080013 ffffffff [ 42.622426] r9:000a9053 r8:002dc6c0 r7:d7045c9c r6:ffffffff r5:a0080013 r4:c045fdfc [ 42.629962] [<c045fdd4>] (_raw_spin_unlock_irq) from [<c02d6544>] (omap_8250_set_termios+0x280/0x388) [ 42.638862] [<c02d62c4>] (omap_8250_set_termios) from [<c02d24e0>] (serial8250_set_termios+0x1c/0x28) [ 42.647751] r10:00000000 r9:c02b4420 r8:ddc4f260 r7:ddc4f1d0 r6:d8288600 r5:d7045d64 [ 42.655354] r4:c0aede34 [ 42.657812] [<c02d24c4>] (serial8250_set_termios) from [<c02cbb14>] (uart_change_speed+0x38/0xdc) [ 42.666371] [<c02cbadc>] (uart_change_speed) from [<c02cc728>] (uart_set_termios+0x7c/0x188) [ 42.674508] r7:ddc4f1d0 r6:c0aede34 r5:d7045d64 r4:d8288600 [ 42.680014] [<c02cc6ac>] (uart_set_termios) from [<c02b7ef4>] (tty_set_termios+0x150/0x1e8) [ 42.688065] r9:c02b4420 r8:00000005 r7:00000000 r6:00001400 r5:d8288680 r4:d8288600 [ 42.695592] [<c02b7da4>] (tty_set_termios) from [<c02b878c>] (set_termios+0x3a8/0x410) [ 42.703227] r8:d7014c80 r7:00000051 r6:d7014c80 r5:00000008 r4:d8288600 [ 42.709748] [<c02b83e4>] (set_termios) from [<c02b8ce0>] (tty_mode_ioctl+0x494/0x5ac) [ 42.717297] r7:d8288600 r6:d8367840 r5:befb5b64 r4:d8288600 [ 42.722805] [<c02b884c>] (tty_mode_ioctl) from [<c02b8e44>] (n_tty_ioctl_helper+0x4c/0x10c) [ 42.730857] r8:d7014c80 r7:d8288600 r6:d8367840 r5:d8288600 r4:befb5b64 [ 42.737379] [<c02b8df8>] (n_tty_ioctl_helper) from [<c02b44c4>] (n_tty_ioctl+0xa4/0x144) [ 42.745181] r5:00005402 r4:befb5b64 [ 42.748654] [<c02b4420>] (n_tty_ioctl) from [<c02b1edc>] (tty_ioctl+0x4dc/0xe8c) [ 42.755785] r7:befb5b64 r6:d8367840 r5:00005402 r4:d8288600 [ 42.761294] [<c02b1a00>] (tty_ioctl) from [<c00f14c8>] (do_vfs_ioctl+0x460/0x6dc) [ 42.768510] r9:00000007 r8:befb5b64 r7:00000007 r6:d8367840 r5:ddf2a4a8 r4:befb5b64 [ 42.776039] [<c00f1068>] (do_vfs_ioctl) from [<c00f17b8>] (SyS_ioctl+0x74/0x84) [ 42.783087] r10:00000000 r9:00000007 r8:befb5b64 r7:00005402 r6:d8367840 r5:d8367841 [ 42.790690] r4:00000000 [ 42.793150] [<c00f1744>] (SyS_ioctl) from [<c000fb60>] (ret_fast_syscall+0x0/0x44) [ 42.800448] r9:d7044000 r8:c000fd24 r7:00000036 r6:00000000 r5:000018bd r4:00000000