i.MX Processors中的主题 Re: imx cpufreq setting

imx cpufreq setting

brkantor — Fri, 07 Oct 2011 13:37:08 GMT

I work on lowering of imx28 power consumption.

I seemed, there are available frequencies: 454, 360 and 261MHz.

Is it possible to use 64MHz mentioned in imx28 documentation?

BTW

How about cpuidle?

Are there any plans to use it on imx28?

Re: imx cpufreq setting

PavelNakonechny — Fri, 07 Oct 2011 13:44:33 GMT

There is mistake in cpufreq.c with calculation of variables lcd_on_freq_table_size and lcd_off_freq_table_size.

Fix them accordingly for your board, and enjoy minimal frequency. This works for our board based on i.MX287:

lcd_on_freq_table_size = ARRAY_SIZE(profiles);
lcd_off_freq_table_size = ARRAY_SIZE(profiles);

:-)

Re: imx cpufreq setting

AhmetYUCE — Fri, 07 Oct 2011 14:15:53 GMT

CPU Idle is available and working on iMX8, just turn it on in the kernel settings. Regarding CPUFreq, there is a bug in BSP or silicon issue. Changing CPU core freq to 454,360 and 261MHz not a problem. But in parallel CPUFreq driver also changes EMI freq into 200,166 and 133MHz, which leads to lockup. 200MHz EMI for all three core freq is safe and working. 133MHz definitely not working. 166Mhz, well it depends. Just check out the discussion i've started few months ago. Regards Ahmet

Re: imx cpufreq setting

TimWoodham — Mon, 17 Oct 2011 04:14:42 GMT

I've found it is possible with mDDR ram.