<div dir="ltr">Hello<div class="gmail_extra"><br><div class="gmail_quote">On Mon, Jun 9, 2014 at 5:56 PM, Peter Stuge <span dir="ltr"><<a href="mailto:peter@stuge.se" target="_blank">peter@stuge.se</a>></span> wrote:<blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">

The noise is created by switching between states.<br>
<br>
I expect that the noise comes from power supply circuitry.<br>
<br>
Use an oscilloscope in clever ways to find the source.<br></blockquote><div><br></div><div>I don't have an oscilloscope, however I created the following script following glugglug suggestion - it fixes the noise (and also add some battery life) : <a href="http://pastebin.ca/2816554">http://pastebin.ca/2816554</a></div>

<div><br></div><div><div>## reduce sound power consumption (only works while everything is muted)</div><div>amixer set Master mute nocap</div><div>amixer set CD mute nocap</div><div>amixer set Mic mute nocap</div><div>echo 'Y' > /sys/module/snd_hda_intel/parameters/power_save_controller</div>

<div>echo '1' > /sys/module/snd_hda_intel/parameters/power_save</div><div> </div><div>## reduce SATA power consumption</div><div>for i in /sys/class/scsi_host/host*/link_power_management_policy; do echo 'min_</div>

<div>power' > $i; done</div><div> </div><div>## reduce USB power consumption with autosuspend</div><div>for i in /sys/bus/usb/devices/*/power/autosuspend; do echo '1' > $i; done</div><div>for i in /sys/bus/usb/devices/*/power/control; do echo 'auto' > $i; done</div>

<div> </div><div>## other powertop recommanded settings</div><div>echo '0' > '/proc/sys/kernel/nmi_watchdog'</div><div># 15 seconds by default, use 60 instead</div><div>echo '6000' > '/proc/sys/vm/dirty_writeback_centisecs'</div>

<div>echo '1' > '/sys/module/snd_hda_intel/parameters/power_save'</div><div>echo 'min_power' > '/sys/class/scsi_host/host0/link_power_management_policy'</div><div>echo 'auto' > '/sys/bus/usb/devices/5-1/power/control'</div>

<div>echo 'auto' > '/sys/bus/pci/devices/0000:05:00.2/power/control'</div><div>echo 'auto' > '/sys/bus/pci/devices/0000:00:1b.0/power/control'</div><div>echo 'auto' > '/sys/bus/pci/devices/0000:00:1c.0/power/control'</div>

<div>echo 'auto' > '/sys/bus/pci/devices/0000:00:1c.1/power/control'</div><div>echo 'auto' > '/sys/bus/pci/devices/0000:00:1c.2/power/control'</div><div>echo 'auto' > '/sys/bus/pci/devices/0000:00:1c.3/power/control'</div>

<div>echo 'auto' > '/sys/bus/pci/devices/0000:00:1d.1/power/control'</div><div>echo 'auto' > '/sys/bus/pci/devices/0000:00:1d.2/power/control'</div><div>echo 'auto' > '/sys/bus/pci/devices/0000:00:1d.3/power/control'</div>

<div>echo 'auto' > '/sys/bus/pci/devices/0000:00:1f.1/power/control'</div><div>echo 'auto' > '/sys/bus/pci/devices/0000:00:1f.2/power/control'</div><div>echo 'auto' > '/sys/bus/pci/devices/0000:00:02.0/power/control'</div>

<div>echo 'auto' > '/sys/bus/pci/devices/0000:00:00.0/power/control'</div><div>echo 'auto' > '/sys/bus/pci/devices/0000:00:1d.0/power/control'</div><div>echo 'auto' > '/sys/bus/pci/devices/0000:01:00.0/power/control'</div>

<div>echo 'auto' > '/sys/bus/pci/devices/0000:02:00.0/power/control'</div><div>echo 'auto' > '/sys/bus/pci/devices/0000:05:00.0/power/control'</div><div>echo 'auto' > '/sys/bus/pci/devices/0000:05:00.1/power/control'</div>

<div>echo 'auto' > '/sys/bus/pci/devices/0000:00:1d.7/power/control'</div></div><div> </div><blockquote class="gmail_quote" style="margin:0px 0px 0px 0.8ex;border-left-width:1px;border-left-color:rgb(204,204,204);border-left-style:solid;padding-left:1ex">

Factory BIOS and coreboot have different noise.<br></blockquote><div><br></div><div>All I'm left is with a very small crackling noise, seemingly coming from the right handside (where the audio jacks are). A new noise, because I can't remember ever hearing it :-)</div>

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