How to enable multi-core for i.MX6 dual.

[trongthinh]

Hi all,

I found that only one CPU online on my i.MX6 Dual. 

processor : 0
model name : ARMv7 Processor rev 10 (v7l)
BogoMIPS : 3.00
Features : 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

This is the kernel source that i use. I didn't modify any file in source code. My device tree include imx6q.dtsi which includes 4 CPUs declaration insight.

https://github.com/Freescale/linux-fslc.git

Can any one give advice? Any suggest is welcome.

Thank all.

[Carlos_Musich]

Hi,

- Can you share the full part number of the device you are using?

- What MACHINE did you use when you built Linux image?

- Can you share the output of cat /proc/cpuinfo?

- Note that in uboot you can modify the number of cpus that will be enabled at boot time, you can change this in bootargs with variable max_cpus. If this variable is not set then the default is all the available cpus.

Regards,

Carlos

[trongthinh]

Hi Carlos,

- This is full part number

MCIMX6D7CVT08AD

- This is the MACHINE I used

meta-freescale, branch morty lasted commit, MACHINE = imx6qsabresd.conf.

note: I created my custom machine, but I simply copy and rename the file above.

- This is all content of /proc/cpuinfo

processor : 0
model name : ARMv7 Processor rev 10 (v7l)
BogoMIPS : 3.00
Features : 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

- I did not set variable max_cpus in u-boot env.

Best Regards,

Thinh

[Carlos_Musich]

Hi Thinh,

If you are sure that bootargs are not set to use only one CPU the it looks like hardware issue. Did you burned the fuses?

[trongthinh · Accepted solution]

Hi Carlos,

I am sure that maxcpus arg is not set in my u-boot environment. Therefore, I tried to set maxcpus=2 in boot arg and i found that 2 CPU were online. Why I need to set this bootarg? i.MX6q/i.MX6D are multi-core, I suggest this bootarg should be default.

[Carlos_Musich]

I agree, I will check that.