CMA setting on colibri-imx6ull

Dear community, we already had a similar problem on colibri-imx6 reported here and as suggested from @stefan.tx setting the CMA to 32 in the kernel solves our problem.
Now I try to do the same thing in the kernel 4.9.23.x from the BSP 2.8 but nothing changed on the run time, the CMA is always set to the default of 128MB, even if I pass the argument from u-boot.

In the @stefan.tx last answer it tells that with newer kernels it could be necessary to change the device tree, but I don’t know how. Can you point me to a more detailed documentation or example on how to set the CMA to 32MB value in the kernel 4.9-2.3.x ?

Thank you for your help,

Hi @Stefano

What is your application? Why do you want to change CMA? Have you seen any issue regarding your use-case?

Best regards, Jaski

Hi @jaski.tx , yes, we encounter an issue when we request to use more than 50% of the RAM memory. As explained in the previous post, changing the CMA to 32MB solve our problems.

Best, Stefano.

Hi @Stefano

You can set the size attribute to the value of your choice and flash the compiled custom devicetree to the module.

Best regards,

Hi @jaski.tx, this works for me.

Thank you for the support.


Perfect that it works. Thanks for the feedback.