SMP configuration in imx6dual SoC

[dilshad_alam]

We are using the dual core iMX6 chip on our target board running Freescale Kernel 3.14.28).

We are trying to enable both the cores but unable to detect the second core.

I have done following modification in defconfig.

CONFIG_GENERIC_SMP_IDLE_THREAD=y

CONFIG_HAVE_SMP=y

CONFIG_SMP=y

CONFIG_SMP_ON_UP=y

CONFIG_PM_SLEEP_SMP=y

and imxdl.dtsi is by default has cpu@1 nodes enabled.

cpu@1 {

  compatible = "arm,cortex-a9";

  device_type = "cpu";

  reg = <1>;

  next-level-cache = <&L2>;

  };

Please find the Kernel logs:-  These logs does not come if don't enable CONFIG_SMP

[    0.082439] CPU0: thread -1, cpu 0, socket 0, mpidr 80000000

[    0.088239] Setting up static identity map for 0x10427398 - 0x104273f0

[    0.100426] Brought up 1 CPUs

[    0.103494] SMP: Total of 1 processors activated.

[    0.108341] CPU: All CPU(s) started in SVC mode.

cat /proc/cpuinfo

processor       : 0

model name      : ARMv7 Processor rev 10 (v7l)

Features        : swp half thumb fastmult vfp edsp neon vfpv3 tls vfpd32

CPU implementer : 0x41

CPU architecture: 7

CPU variant     : 0x2

CPU part        : 0xc09

CPU revision    : 10

Hardware        : Freescale i.MX6 Quad/DualLite (Device Tree)

Revision        : 0000

Serial          : 0000000000000000

Let me know if i am missing anything.

Thanks,

Dilshad

[dilshad_alam · Accepted solution]

This Problem is resolved. CONFIG_CMDLINE was having parameter "nosmp". After removing that, both the cores are detected.

[igorpadykov]

Hi Dilshad

one can check maxcpus kernel parameter and how many

cores in chip: fuse NUM_CORES 0x430[21:20]

Table 5-8. Fusemap i.MX6SDL RM rev.2 (5/2015).

Default kernel imx_v7_defconfig should support smp.

Best regards

igor

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[dilshad_alam]

Hi Igor,

Thanks for your reply.

I have checked NUM_CORES 0x430[21:20] bit values. Its coming as  0xA20100C4. Bit 20 & 21 are 00 which means its dual core as per TRM.

Do you see any problem in my configs.

in CONFIG_CMDLINE also i added maxcpus=2   but still its not recognized.

Any further inputs in debugging this issue would be appreciated.

Thanks,

Dilshad

[igorpadykov]

HI Dilshad

could you try Demo images from i.MX6 product page :

Board Support Packages (27)

L3.14.28_1.0.0_iMX6QDLS_BUNDLE (REV L3.14.28_1.0.0)

i.MX 6Quad, i.MX 6Dual, i.MX 6DualLite, i.MX 6Solo Linux Binary Demo Files and Linux BSP Documentation

SABRE Board Reference Design|Freescale

L3.14.28_1.0.0_iMX6QDLS_BUNDLE (REV L3.14.28_1.0.0)

i.MX 6Quad, i.MX 6Dual, i.MX 6DualLite, i.MX 6Solo Linux Binary Demo Files and Linux BSP Documentation

Best regards

igor

[dilshad_alam]

Hi Igor,

This is cutomized board based on SabreSD.

I doubt kernel booting with Demo Images and moreover it will not solve my issue.

It would be great if you can give pointers in debugging this issue?

Thanks,

Dilshad