topic i.MX8m-mini DRAM Controller in i.MX Processors

i.MX8m-mini DRAM Controller

JamesShih — Fri, 30 May 2025 21:55:29 GMT

Hi,

I followed the linux ref manual 2.5.4 and able to control the bus frequency, but it seems like not control the DRAM controller directly, correct?

If yes, what if I would like to control the DRAM Controller directly? Or I can do both at the same time?

Thanks.

James Shih

Re: i.MX8m-mini DRAM Controller

pengyong_zhang — Wed, 04 Jun 2025 08:16:42 GMT

Hi @JamesShih

What do you mean control the DRAM Controller directly? please explain more details

B.R

Re: i.MX8m-mini DRAM Controller

JamesShih — Wed, 04 Jun 2025 21:34:08 GMT

Hi Pengyong,

Sorry for the incomplete information, the DRAM Controller I mean is the DDR Controller.

Right now in my environment, I'm able to use "busfreq" to set DDR and NOC to the lower frequency and for sure able to see the power consumption going down.

Beside, there is another one called "devfreq", I tried to enable it in my environment, but unfortunately it didn't work and even not able to see the node.

To clarify my question, I just want to confirm if in the same clock (lower frequency) condition by either busfreq or devfreq, from the power consumption point of view it shouldn't be any different, correct?

Hopefully it's clear for you to understand my question, thanks.

Re: i.MX8m-mini DRAM Controller

pengyong_zhang — Thu, 05 Jun 2025 07:03:56 GMT

Hi @JamesShih

NXP vendor tree is using a private busfreq [1] driver to do ddr and bus fabric scalling rather than using upstream ddrc & interconnect
driver which is still immature. And actually there's no i.MX driver users of ICC in current vendor kernel. So removing them in order to avoid confusing to customers

B.R

Re: i.MX8m-mini DRAM Controller

JamesShih — Thu, 05 Jun 2025 18:20:23 GMT

Thanks, it's clear for me now.