Stuck on Calibrating delay loop...

sharethl · 10-17-2015, 03:23 PM

I used buildroot to compile kernel for imx6, but stuck on here, how to configure clocksource?

Thanks

Code:

Starting kernel ...

Uncompressing Linux... done, booting the kernel.
Booting Linux on physical CPU 0x0
Initializing cgroup subsys cpuset
Initializing cgroup subsys cpu
Linux version 4.2.3 (tonghua@tonghua-virtual-machine) (gcc version 4.9.2 20140904 (prerelease) (crosstool-NG linaro-1.13.1-4.9-2014.09 - Linaro GCC 4.9-2014.09) ) #4 SMP PREEMPT Sat Oct 17 13:30:22 EDT 2015
CPU: ARMv7 Processor [412fc09a] revision 10 (ARMv7), cr=10c5387d
CPU: PIPT / VIPT nonaliasing data cache, VIPT aliasing instruction cache
Machine: Generic DT based system
bootconsole [earlycon0] enabled
Memory policy: Data cache writeback
CPU: All CPU(s) started in SVC mode.
PERCPU: Embedded 11 pages/cpu @9fbe9000 s14656 r8192 d22208 u45056
Built 1 zonelists in Zone order, mobility grouping on.  Total pages: 130048
Kernel command line: console=ttymxc0,115200n8 root=/dev/nfs nfsroot=192.168.1.31:/nfsroot ip=dhcp earlyprintk clocksource=imx_timer1
PID hash table entries: 2048 (order: 1, 8192 bytes)
Dentry cache hash table entries: 65536 (order: 6, 262144 bytes)
Inode-cache hash table entries: 32768 (order: 5, 131072 bytes)
Memory: 510684K/524288K available (6854K kernel code, 250K rwdata, 1208K rodata, 288K init, 411K bss, 13604K reserved, 0K cma-reserved, 0K highmem)
Virtual kernel memory layout:
    vector  : 0xffff0000 - 0xffff1000   (   4 kB)
    fixmap  : 0xffc00000 - 0xfff00000   (3072 kB)
    vmalloc : 0xa0800000 - 0xff000000   (1512 MB)
    lowmem  : 0x80000000 - 0xa0000000   ( 512 MB)
    pkmap   : 0x7fe00000 - 0x80000000   (   2 MB)
    modules : 0x7f000000 - 0x7fe00000   (  14 MB)
      .text : 0x80008000 - 0x807e7de4   (8064 kB)
      .init : 0x807e8000 - 0x80830000   ( 288 kB)
      .data : 0x80830000 - 0x8086ea00   ( 251 kB)
       .bss : 0x8086ea00 - 0x808d58fc   ( 412 kB)
SLUB: HWalign=64, Order=0-3, MinObjects=0, CPUs=1, Nodes=1
Preemptible hierarchical RCU implementation.
        Additional per-CPU info printed with stalls.
        Build-time adjustment of leaf fanout to 32.
        RCU restricting CPUs from NR_CPUS=4 to nr_cpu_ids=1.
RCU: Adjusting geometry for rcu_fanout_leaf=32, nr_cpu_ids=1
NR_IRQS:16 nr_irqs:16 16
clocksource_of_init: no matching clocksources found
sched_clock: 32 bits at 100 Hz, resolution 10000000ns, wraps every 21474836475000000ns
Console: colour dummy device 80x30
Calibrating delay loop...

jpollard · 10-18-2015, 11:45 AM

You might not have a hardware clock (my Raspberry PI doesn't - it skips the calibration step and uses the timer frequency to compute a calibration).

If that is the case for your system, that would explain why it is hanging.

If you have an original kernel, you should have a config file that works. I would suggest comparing yours with it to see what is different (and skip the parts that HAVE to be different due to your module).

sharethl · 10-18-2015, 12:02 PM

Quote:

Originally Posted by jpollard

You might not have a hardware clock (my Raspberry PI doesn't - it skips the calibration step and uses the timer frequency to compute a calibration).

If that is the case for your system, that would explain why it is hanging.

If you have an original kernel, you should have a config file that works. I would suggest comparing yours with it to see what is different (and skip the parts that HAVE to be different due to your module).

Hi, Jpollard,

I copied the working linux kernel 3.0.35 config, and use it on kernel 4.2.3,
after some tweaks, I got different error but same result.

Code:

[    0.000000] i.MX timer: unable to get clk
[    0.000000] sched_clock: 32 bits at 100 Hz, resolution 10000000ns, wraps every 21474836475000000ns
[    0.000000] Console: colour dummy device 80x30
[    0.000000] Calibrating delay loop...

This is the device tree, about timer from 3.0.35.

Code:

timer@00a00600 {
			compatible = "arm,cortex-a9-twd-timer";
			reg = <0x00a00600 0x20>;
			interrupts = <1 13 0xf01>;
			clocks = <&clks 15>;
		};

this is from kernel 4.2.3

Code:

timer@00a00600 {
			compatible = "arm,cortex-a9-twd-timer";
			reg = <0x00a00600 0x20>;
			interrupts = <1 13 0xf01>;
			interrupt-parent = <&intc>;
			clocks = <&clks 15>;
		};

This is the link to the config I used.
https://github.com/TechNexion/linux/...airy_defconfig

jpollard · 10-18-2015, 12:24 PM

I don't have an a9....(a v7l)

My system doesn't have CONFIG_HAVE_SCHED_CLOCK (it does have CONFIG_GENERIC_SCHED_CLOCK), I'm using kernel version 4.1.7-v7+ for the PI 2 (an ARMv7 Processor rev 5 (v7l) ).

The only think I can think of is that the system is expecting a clock interrupt and isn't getting one.

Sorry - you might have to wait for someone with an a9 for better answers.