Re: HTC Dream aka. t-mobile g1 support

From: Brian Swetland
Date: Fri Jun 12 2009 - 18:36:22 EST


On Fri, Jun 12, 2009 at 3:31 PM, Pavel Machek<pavel@xxxxxx> wrote:
>> > Is there a reason that this couldnt be done in userspace?
>>
>> It'd be a lot more overhead -- in some cases it's updated with
>> relatively fine granularity (wifi driver changing state, backlight
>> changing, etc), and on the kernel side it's just updating a shared
>> memory location with the current estimate. ÂUserspace doesn't
>> necessarily have the visibility into driver state to update it
>> accurately, and punching that information down to userspace and then
>> having userspace feed it back up to the kernel seems like more
>> overhead and code to maintain to me.
>
> Actually I agree with Brian here, this is better done at kernel level.
>
> OTOH, at least initially, it does not need to be done at all. It will
> make battery readings less reliable but hey... the battery meter does
> not work reliably anyway and estimating capacity left from voltage
> acceptably on other platforms...

I'd agree. This stuff can wait until the core support is solid. I'd
fight harder for conditional support for wakelocks since that has a
much bigger impact on battery life (being able to know when it's safe
to power collapse in idle, etc), whereas this just improves the
accuracy of the battery gauging.

Brian
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/