pm39

Well nuts; I didn't search enough. The workaround detailed here: ...looks like it's working for me.

Greetings, all! I've got a LeMaker A20 BananaPro, on which I'm using the Armbian mainline distribution (for a more complete description of my setup, please see below). I'm using a serial console to the board; I'm not connecting anything to HDMI for display. I'm running the distribution off of a brand new 8Gig SanDisk Extreme Pro. I would like to use alsa (at least in part) in the audio stack. I'm experiencing the following: When I have no audio playing through the audio out jack, I get a loud (powerline, probably) hum on my speakers. When I start audio playback (a wav through aplay, or an mp3 through mpd, etc.) the hum disappears, and the sound quality is fine. If I pause or stop playback, the hum resumes roughly seven seconds after the audio stops. The pause between the audio stopping and the hum seems consistant. I have found in my research a similar problem people have been having with Ubuntu: http://www.linuxquestions.org/questions/linux-general-1/buzzing-sound-from-speakers-only-when-no-sound-is-playing-ubuntu-kk-790610/ ...which seems to be due to a power saving feature of the driver, but I can't find any reference to a similar feature for the sun4i_codec module. Can anyone offer assistance? I'm not sure what to try next. I'm very happy to test things, try things, etc. Thanks! -Paul Various configuration details below. Results of uname -a: Linux hostname 4.9.12-sunxi #4 SMP Thu Feb 23 19:46:51 CET 2017 armv7l GNU/Linux Contents of /etc/armbian-release: # PLEASE DO NOT EDIT THIS FILE BOARD=bananapipro BOARD_NAME="Banana Pi Pro" VERSION=5.25 LINUXFAMILY=sunxi BRANCH=next ARCH=arm IMAGE_TYPE=stable Results of lsmod: Module Size Used by sun4i_codec 10104 3 snd_soc_core 97876 1 sun4i_codec ir_lirc_codec 4088 0 snd_pcm_dmaengine 2770 1 snd_soc_core evdev 9412 1 lirc_dev 6245 1 ir_lirc_codec snd_pcm 57757 3 snd_pcm_dmaengine,snd_soc_core snd_timer 14809 1 snd_pcm snd 35783 4 snd_timer,snd_soc_core,snd_pcm sun4i_ts 3414 0 soundcore 858 1 snd sunxi_cir 3159 0 nvmem_sunxi_sid 1967 0 nvmem_core 7158 1 nvmem_sunxi_sid sun4i_ss 13213 0 cpufreq_dt 2920 0 uio_pdrv_genirq 2780 0 uio 6272 1 uio_pdrv_genirq bonding 82855 0 brcmfmac 144129 0 brcmutil 4189 1 brcmfmac cfg80211 337391 1 brcmfmac rfkill 8383 2 cfg80211 fuse 62841 1 realtek 2583 0