William Lovaton wrote:
> Hello there,
> 
> I've been tweaking my laptop to reduce wake ups and power consumption
> and so far everything has been great.  Later I'll post my experience to
> share it with all of you but before I want to ask a question I have.
> 
> I discovered that the dcdbas driver doesn't seem to be causing wake ups
> but interestingly it was consuming actual power according to my trusty
> Kill A Watt P3 device.
> 
> With the driver removed the power consumption is about 14 watts
> sometimes getting up to 15, but it stays in 14 most of the time.  When I
> insert the driver back it starts to fluctuate randomly between 14 and 19
> but it doesn't stay in 14 as much as before.  I can reproduce this every
> time by simply removing or adding the driver.

alternatively, you can just measure power consumption over time and get a more
consistent view of the extra usage (e.g. measure 10 minutes with/without) if 
your
kill a watt supports that.

> So, as far as I could find dcdbas is a Dell driver for controlling the
> SMBIOS or something like that, if someone can explain to me what it
> does, please do.

from the kernel sources:

 *  The Dell Systems Management Base Driver provides a sysfs interface for
 *  systems management software to perform System Management Interrupts (SMIs)
 *  and Host Control Actions (power cycle or power off after OS shutdown) on
 *  Dell systems.

basically it frobs in firmware to make the firmware do things like 
shutdown/reboot
etc.

> Is this driver actually necessary? 

I can't tell. try running without it and see if you can shutdown/reboot/suspend
normally.

> how can I blacklist it to prevent it
> from being loaded on every boot? Does anyone with a Dell laptop can
> reproduce this?

you can remove the module from the modules folder, or you can add a line to
/etc/modprobe.conf:

blacklist dcdbas

I've never actually tried this myself though

> But more importantly, where do I file a bug report so it gets fixed?

check MAINTAINERS, in your kernel source tree:

DELL SYSTEMS MANAGEMENT BASE DRIVER (dcdbas)
P:      Doug Warzecha
M:      [EMAIL PROTECTED]
S:      Maintained



Cheers,

Auke

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