Frame rate drops and not recovers in i.Mx6 MIPI-CSI

[salihns]

Hi,

We are using i.Mx6 QuadPlus Nitrogen Board with Kernel Version 3.14.52. We are using propriety MIPI Camera with our customized driver through MIPI-CSI2 interface. We are setting the resolution as 120x120 and just do continuous streaming via simple bare metal application. Initially we are getting the expected Frame rate of 120fps. We are trying to increase the load, so we compiling some pieces of code with Makefile (make -j4) which enables all the four cores. At that moment, the frame rate is reducing to 38fps and not recover to the actual fps even we stopped the compilation.

Please let me know the reason for the above issue and provide the solution for the same.

Thanks in advance.

Regards,
Salih

[igorpadykov]

Hi Salih

one can try parameter isolcpus=[cpu_number] in linux kernel command,

this will instruct the linux scheduler to no run any regular tasks on that cpu.

The kernel’s command-line parameters — The Linux Kernel documentation 

Use cpu affinity to fix your specific task to the isolated cpu.

i.mx6 Linux CPU IRQ affinity 

Best regards
igor
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