Re: RFA: acpi-support -- glue layer for translating laptop buttons, plus legacy suspend support

[Giacomo Catenazzi <cate@debian.org>]

Michael Biebl wrote:
> Giacomo A. Catenazzi wrote:
>> Michael Biebl wrote:
>>> Roger Leigh wrote:
>>>> On Mon, Apr 20, 2009 at 05:52:41PM +0200, Michael Biebl wrote:
>>>>> Roger Leigh wrote:
>>>>>
>>>>>> On Mon, Apr 20, 2009 at 03:55:15PM +0200, Michael Biebl wrote:
>>>>>>> hal does not poll removable disks, it does though poll cd-rom drives for new
>>>>>>> media and afaik there is no way around that if you want automount for cdrom
>>>>>>> drives to work
>>>>>> Spinning up the CD drive every 30 seconds is simply not an acceptable
>>>>>> "solution".  If that's the best HAL can do, it should be disabled by
>>>>>> default, and users will simply have to select the device by hand; we're
>>>>>> only talking about automatic mounting here, after all.
>>>>> First, polling the cd drive for new media should not spin it up. If it does it
>>>>> is most likely a kernel/driver or firmware bug.
>>>> So the bug is in a kernel driver, possibly.  But, it's still hal
>>>> triggering the bug by the continual polling.
>>>>
>>>>> Second, you can very easily disable this behaviour: man hal-disable-polling
>>>> Great, but it's still not the default behaviour.  Does every
>>>> user need to find out how to disable it after they become sufficiently
>>>> annoyed by the constant spinning up of their CD drive?
>>> Why should *every* user need to find out? Seems to me as if you are exaggerating
>>> in order to make a point. For the majority of users it just works, that's why it
>>> is the default.
>> powertop encourages to disable polling, so it is a big point.
> 
> I agree with you in general, but I doubt polling every 2 or 16 seconds will make
> any significant difference power consumption wise.


Recently it was discovered that a blinking cursor consumes a lot of power
(blink is normally between 1 and 2 second interval).
I think it should be the same, in this case.
Take into account that both uses hardware, thus not allowing some chips
to rests.

I've no machine (maybe misconfiguration) with powertop indicating
the power demand.  Could someone do some tests?
(hal-disable-polling has the option also to enable the pooling)

> 
>> "Majority of users it just works", but how many of such user will use this feature?
> 
> How shall I answer that?
> I know that I myself use auto-mounting extensively and also don't expect my
> father to type someting like "mount /dev/hdc /mnt/cdrom"

On the other side, it was considered a bad idea for the security standpoint.
[Remember also the "audio CD" with also some data (and maybe the famous
old windoze rootkit.  Which kind of CD is recognized? Could user recognize
from CD which action will be done?]

IMHO the right thing to do is "automount", when people try to access the
right directory (filemanager, open dialog windoze, ...).

For these two reason (power and security), I think Debian should offer
a debconf question, (medium priority), about disabling pooling.

ciao
	cate