[Gta04-owner] Now that 3.2-final is out...

Radek Polak psonek2 at seznam.cz
Mon Jan 9 11:32:14 CET 2012


On Sunday 08 January 2012 22:43:28 NeilBrown wrote:

> On Sun, 8 Jan 2012 16:56:03 +0000 Radek Polak <psonek2 at seznam.cz> wrote:
> > I tested 3.2-gta04 quickly. I will do more tests probably tomorrow. For
> > now suspend seems to work fine, but after resume the display starts
> > blinking and the image shifts up and down. I can take a video if needed.
> > I think i had the same problem with previous rc too.
> 
> Hmmm... that is unfortunate, though it doesn't surprise me a whole lot.
> 
> I spent a while examining 'cpuidle' which is supposed to put the CPU in
> low-power states when idle.  But it doesn't.
> 
> You can confirm by something like:
> 
>    grep . /sys/devices/system/cpu/cpu0/cpuidle/state?/usage
> 
> That will report how often it was in each state (I don't know what the
> units are).  All states > 0 have a usage of 0.

yes

> The reason is that the UART loses characters when you drop to a lower power
> state so it refuses to do it when the UART is active - which is always.
> 
> You can adjust this with the "sleep_timeout" setting - 1 per uart.  I don't
> remember exactly where in sysfs this is:
>    find /sys -name sleep_timeout
> 
> 
> If you set all these to (say) 10 (seconds), then after 10 seconds of no
> uart activity it will drop to lower power states.  I've measure an idle
> current below 100mA.

yes, there are now usages also in states > 0

> However other things than the UART stop working.
> 
> One it the battery monitor (bq27000) - it just fails to report meaningful
> values.
> The other (and this is where you get to see the relevance of this
> diversion) is the DSS - display sub system.  It reports something about
> losing sync and gets into a loop where it keeps disabling and re-enabling
> the display.

Yes this is exactly the same effect as after resume. Btw i forget to report, 
that when i press "Power off" in QtMoko which probably calls halt, then the 
screen stops flashing and shifting and is ok again.

> (I only managed to measure current by getting the display to blank first).
> 
> Do maybe if you make sure to blank the display before suspending it might
> wake up again properly after resume??

I tried:
	
	echo 1 > /sys/devices/platform/omapfb/graphics/fb0/blank
	sleep 10
	echo mem > /sys/power/state

but that did not help. After pressing POWER i have the same problem with this 
message in dmesg:

omapdss DISPC error: SYNC_LOST on channel lcd, restarting the output with 
video overlays disabled

Regards

Radek


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