[Community] GTA04 - Standby Time, Stable Kernel and Voice Quality

[Jake Drexel]

Thanks Neil and Radek for your enlightening answers.

Looks like a GTA04 can only be a step forward!

Jake

On 1/23/13, NeilBrown <neilb at suse.de> wrote:
> On Tue, 22 Jan 2013 12:35:38 +0100 Jake Drexel <jackramone at googlemail.com>
> wrote:
>
>> Hi all,
>>
>> As a current user of the gta02 I am concerned about the state of some
>> shortcomings it had or still has in regard to the gta04.
>>
>> Could someone share their experience in respect to:
>>  * standby time (different scenarios, especially working as a phone only)
>
> I think the current drain on the battery while the main CPU is suspended
> but
> the 3G module is active, but in reasonably good coverage area, can
> definitely
> get below 20mA, probably 15mA.  With GTA04A4 should be able to get a little
> lower, maybe 10mA.
>
> I have "off-mode" working in my current kernel (so most of the OMAP3 powers
> off completely during suspend) which helped get from around 20mA down to
> around
> 15. Not completely certain of the results yet.  The A5 allows a couple more
> components to be powered off completely which should save a couple of mA
> each.
>
> A new battery claims 1200mAh, so that would be 120 hours or 5 days.  The
> battery I'm using isn't that new, I only have the A3, and it has some
> strange
> hardware issues (self inflicted) which I haven't figured out yet so I don't
> get much more than 24hrs - I simply charge it every night.  I have
> "off-mode"
> working in my current kernel (so most of the OMAP3 powers off completely
> during suspend) which helped
>
> Obviously any time spent making calls or surfing the web will reduce that.
> A
> full battery might give you about 3 hours of solid web browsing.
>
>>  * how stable is the kernel? esp. suspending (is that still used for
>> power saving?)
>
> Very stable.  Suspend and resume work quite reliably and quite quickly.  I
> cannot promise it is 100% perfect as new releases come out and bugs do
> creep
> in, but it really is quite solid.
>
> Suspend is currently essential for power saving.  It should in theory be
> possible to get a similar power saving without using suspend by letting
> runtime PM and cpuidle reduce usage when nothing else is happening.
> However
> I think it would be a substantial challenge to achieve that in practice.
> You
> would need very well behaved user-space, and undoubtedly a number of fixes
> and
> improvements to the kernel.  Might be an education project for someone
> though.
>
>
>>  * audio quality while using as a phone
>
> For the A3, which does software voice-routing, the call quality is
> adequate.
> There is some echo, but I've heard worse on the occasional "commercial"
> phone
> from big name vendors.
> For the A4 and A5 the voice-routing is in "hardware" so the latency is
> lower
> and thus there is less room for echo.  I haven't experienced it myself but
> I
> suspect it is a good as most phones.
>
> My biggest problem is that the 3G module is prone to crashing.  I have my
> own
> software that talks to it and it is entirely possible that I'm doing some
> silly things, but as the documentation is very thin it is hard to know what
> I
> should be doing.  With the A3 I cannot power-cycle the modem from software
> so
> I occasionally get into situations where I need to remove the battery.
> For the A4 and A5 it is possible to force a power-cycle so you can
> definitely
> programaticly restore functionality if it appears to be too sick.
>
> The A5 is expected to have newer firmware which will have different bugs -
> hopefully few of them
>
>
>>
>> Thanks for your comments, any answers might bring me (and maybe
>> others) closer to buy a gta04 ;-)
>
> Good! Please buy :-)
>
> NeilBrown
>
>