Madozu

No, that's not needed as rc.local runs with root privileges. The "Sudo Prefix" however is needed when you use your normal login user id to test.

I am running a headless cubietruck with Armbian standard kernel (5.10.4-sunxi as of now). System is Ubuntu Focal Fossa with "linux-focal-root-current-cubietruck 20.11.6" installed. Cubietruck has uboot and /boot on SD-Card and the system is on a SATA-attached SSD. CPU load average over 20s (vmstat 20) is like this: procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu----- r b swpd free buff cache si so bi bo in cs us sy id wa st 0 0 0 1827484 18008 137776 0 0 0 0 121 78 0 5 94 0 0 1 0 0 1827484 18008 137772 0 0 0 0 109 70 0 5 95 0 0 0 0 0 1827232 18008 137776 0 0 0 0 96 57 0 5 95 0 0 1 0 0 1827232 18008 137776 0 0 0 0 102 56 0 5 95 0 0 1 0 0 1827232 18008 137776 0 0 0 0 109 72 0 5 95 0 0 1 0 0 1827232 18008 137776 0 0 0 0 92 49 0 5 95 0 0 2 0 0 1827232 18008 137776 0 0 0 0 95 49 0 5 95 0 0 1 0 0 1827232 18008 137776 0 0 0 0 112 75 0 5 95 0 0 0 0 0 1827232 18008 137776 0 0 0 0 92 52 0 5 95 0 0 This is better than what I saw with older (e.g. 4.x) kernels but still around 5% CPU usage coming from "kworker/1:3-events_freezable_power_". When removing the modules for ADC (sun4i_gpad and sun4i_gpad_iio) the CPU usage drops down to <1% in average: procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu----- r b swpd free buff cache si so bi bo in cs us sy id wa st 1 0 0 1826784 18020 137772 0 0 0 9 41 46 0 0 100 0 0 1 0 0 1826540 18020 137772 0 0 0 0 52 60 0 0 99 0 0 1 0 0 1826540 18020 137772 0 0 0 0 39 44 0 0 100 0 0 1 0 0 1826540 18020 137772 0 0 0 0 39 44 0 0 100 0 0 1 0 0 1826532 18020 137776 0 0 0 1 61 69 0 0 99 0 0 1 0 0 1826532 18020 137776 0 0 0 0 45 48 0 0 100 0 0 1 0 0 1826532 18020 137776 0 0 0 0 34 40 0 0 100 0 0 1 0 0 1826532 18020 137776 0 0 0 0 62 69 0 0 99 0 0 1 0 0 1826532 18020 137776 0 0 0 0 35 41 0 0 100 0 0 1 0 0 1826532 18020 137776 0 0 0 0 34 40 0 0 100 0 0 However as stated previously, removing those kernel modules breaks the CPU temp sensor display in the OS. What I recommend to do is running this command to remove the modules contributing to the CPU consumption: sudo rmmod sun4i_gpadc sun4i_gpadc_iio If you're happy with the result, put the above statement into /etc/rc.local to run at every boot. Blacklisting the above modules in /etc/modprobe.d only partially works as module sun4i_gpadc is loaded anyway.

I tested the recently added sunxi-dev patch to improve the SATA write speed. Here are the results: Board: Cubietruck OS: Ubuntu Bionic (18.04.2), Armbian 5.86 Kernel: 5.1.0 with and without RFC-drivers-ata-ahci_sunxi-Increased-SATA-AHCI-DMA-TX-RX-FIFOs.patch SATA-device: SAMSUNG SSD 830 Series, 256GB Measurement method: dd if=/dev/zero of=/tesfile bs=? count=? oflag=direct bs: measured 4k, 64k and 1M block sizes count: adjusted to ensure that data written is ~500MB Measurements below are made with kernel 5.1.0 without (before) and with the mentioned patch: dd bs Before MB/s After MB/s Increase 4k 13.3 19.0 43% 64k 35.9 82.0 128% 1M 42.5 112.0 164% As you can see, the SATA write speed improved, especially when using larger block sizes. Up to now, no negative side-effects encountered.

Removing the module sun4i_gpadc from the kernel, helps somewhat on my A20 Cubietruck with latest user-built Armbian (5.76, Kernel 4.19.25-sunxi). The constant 5-7% CPU consumption of "kworker-eve" has disappeared, but every 10 seconds the CPU load is still up to 25% for one second (as it did before the module removal). Here's the "vmstat 1" output: root@cubietruck:~# vmstat 1 procs -----------memory---------- ---swap-- -----io---- -system-- ------cpu----- r b swpd free buff cache si so bi bo in cs us sy id wa st 1 0 0 1888928 9680 87180 0 0 59 1 47 54 1 6 93 0 0 0 0 0 1888904 9680 87180 0 0 0 0 32 40 0 0 100 0 0 0 0 0 1888904 9680 87180 0 0 0 0 29 39 0 0 100 0 0 0 0 0 1888904 9680 87180 0 0 0 0 25 38 0 0 100 0 0 0 0 0 1888904 9680 87180 0 0 0 0 38 54 0 0 100 0 0 0 0 0 1888904 9680 87180 0 0 0 0 27 38 0 0 100 0 0 0 0 0 1888904 9680 87180 0 0 0 0 157 42 0 25 75 0 0 0 0 0 1888904 9680 87180 0 0 0 0 40 53 0 0 100 0 0 0 0 0 1888904 9680 87180 0 0 0 0 44 56 0 0 100 0 0 0 0 0 1888904 9680 87180 0 0 0 0 27 40 0 0 100 0 0 0 0 0 1888904 9680 87180 0 0 0 0 27 35 0 0 100 0 0 0 0 0 1888904 9680 87180 0 0 0 0 29 39 0 0 100 0 0 Is there anything I can do beside the removal of the sun4i_gpadc module?

Great work @s_frit ... you made my day! I was playing around with alsamixer on a Nano-PC T4 on Armbian (5.76, Ubuntu Bionic, no GUI) with "limited success". After importing the above quoted state settings, Audio was fine on the 3.5mm audio jack. Now I am successfully using mpd to play music without problems :-D