screen brightness adjusts itself constantly

[Mathijs Veen]

Ubuntu 13.10 (r100) (Touch)

Expected: manualy adjusted screen brightness stays that way, except after period of inactivity, when it goes into power saving mode

Instead: brightness is dimmed after a few seconds

As stated in title, screen brighness adjusts itself constantly: When adjusting brightness manualy, Galaxy Nexus device (maguro) is often dimmed immedeatly to seemingly some kind of default setting.
Usualy, this bug happens within seconds after the brightness is set manualy. Sometimes though, it happens later at (apparently) random moments. On rare occasions, it doesnt happen at all.
On every occasion however, the slider for manual setting stays where it is.

At first, I was thinking it was triggered by an overzealous proximity sensor (which however works perfectly on android). Now I am leaning towards some sort of default setting or automated brightness. Judging from earlier posts on xda and LP, it seems there was such a feature at some stage in the beta. is there some kind of automatic brightness process at work, that overides the manual, but which has no interface?

content of media-info:
Ubuntu 13.10 - armhf (20131017)

mat@Lapbuntu:~$ adb shell getprop ro.cm.device
maguro

[Iain Lane (laney)]

It's not a problem with ubuntu-system-settings; opening a task on powerd (the daemon which controls this)

[Mathijs Veen (matv1)]

Correct. I happened to flash to 14.04 (r. 32) yesterday. I no longer see
this happening. I consider this bug resolved.

I do still see some other issues related with power management but I will
file new bug rep after testing a bit more.
Thnks.

On Wed, Dec 4, 2013 at 5:47 PM, Iain Lane <email address hidden> wrote:

> It's not a problem with ubuntu-system-settings; opening a task on powerd
> (the daemon which controls this)
>
> ** Also affects: powerd
> Importance: Undecided
> Status: New
>
> ** Also affects: powerd (Ubuntu)
> Importance: Undecided
> Status: New
>
> ** Changed in: ubuntu-system-settings (Ubuntu)
> Status: New => Invalid
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1247694
>
> Title:
> screen brighness adjusts itself constantly
>
> Status in PowerD:
> New
> Status in “powerd” package in Ubuntu:
> New
> Status in “ubuntu-system-settings” package in Ubuntu:
> Invalid
>
> Bug description:
> Ubuntu 13.10 (r100) (Touch)
>
> Expected: manualy adjusted screen brightness stays that way, except
> after period of inactivity, when it goes into power saving mode
>
> Instead: brightness is dimmed after a few seconds
>
> As stated in title, screen brighness adjusts itself constantly: When
> adjusting brightness manualy, Galaxy Nexus device (maguro) is often dimmed
> immedeatly to seemingly some kind of default setting.
> Usualy, this bug happens within seconds after the brightness is set
> manualy. Sometimes though, it happens later at (apparently) random moments.
> On rare occasions, it doesnt happen at all.
> On every occasion however, the slider for manual setting stays where it
> is.
>
> At first, I was thinking it was triggered by an overzealous proximity
> sensor (which however works perfectly on android). Now I am leaning
> towards some sort of default setting or automated brightness. Judging
> from earlier posts on xda and LP, it seems there was such a feature at
> some stage in the beta. is there some kind of automatic brightness
> process at work, that overides the manual, but which has no interface?
>
> content of media-info:
> Ubuntu 13.10 - armhf (20131017)
>
> mat@Lapbuntu:~$ adb shell getprop ro.cm.device
> maguro
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/powerd/+bug/1247694/+subscriptions
>

[Michael Hall (mhall119)]

Still happens to me on r116

[Launchpad Janitor (janitor)]

Status changed to 'Confirmed' because the bug affects multiple users.

[Mathijs Veen (matv1)]

@mhall119 Thats weird, I thought it was gone. I havn't been running touch for a couple of weeks now but I will do a fresh install later today and check this. Btw are you also on Maguro?

[Mathijs Veen (matv1)]

yeah. It does still do that.

[Pat McGowan (pat-mcgowan)]

As I see it this is behaving properly, manually changing the brightness is changing the normal in-use setting. It does not mean I no longer want the screen to dim after a period of inactivity.
What is missing is the option to turn off automatic brightness control, along with settings for the inactivity timeouts for dim and suspend.

[Seth Forshee (sforshee)]

On Thu, Jan 16, 2014 at 02:28:26PM -0000, Pat McGowan wrote:
> As I see it this is behaving properly, manually changing the brightness is changing the normal in-use setting. It does not mean I no longer want the screen to dim after a period of inactivity.
> What is missing is the option to turn off automatic brightness control, along with settings for the inactivity timeouts for dim and suspend.

The powerd dbus api to allow changing the brightness and {en,dis}abling
autobrightness has been ready for months, just waiting for someone to
approve the merge request. Until that happens there is no way to apply
the user settings.

Inactivity timeouts are a different topic, but I will interject that the
plan has long been for unity to take over this functionality. I don't
think it makes sense to plumb in any apis for changing this in powerd
when that functionality will be removed.

[Mathijs Veen (matv1)]

@pat-mcgowan So you are saying that when my screen dims instantly, it would be caused by default autobrightness behaviuor? I have considered that but I cant really support that assumption. it seems to do this under any given lighting condition.

Also, if your assuption of the cause of this is correct, Inactivity timeouts indeed have nothing to do with this issue. I see inactivity kicking like clockwork at about 40 secs (is that the default currently?). It would be nice to get a ui control for this but that is unrelated. If Unity (8 I presume?) will be solving this, thats great.

[Michael Frey (mfrey)]

We have an MR that will allow you to disable auto brightness.

[Mathijs Veen (matv1)]

This is the merge that Seth Forshee was refering to as well? In that case,
I would love to see this merged then. Not 100% sure if it will solve my
issue, but it seems likely. And there is no doubt that that feature is
needed regardless.

On Fri, Jan 17, 2014 at 3:17 PM, Michael Frey <email address hidden>wrote:

> We have an MR that will allow you to disable auto brightness.
>
> --
> You received this bug notification because you are subscribed to the bug
> report.
> https://bugs.launchpad.net/bugs/1247694
>
> Title:
> screen brighness adjusts itself constantly
>
> Status in PowerD:
> New
> Status in “powerd” package in Ubuntu:
> Confirmed
> Status in “ubuntu-system-settings” package in Ubuntu:
> New
>
> Bug description:
> Ubuntu 13.10 (r100) (Touch)
>
> Expected: manualy adjusted screen brightness stays that way, except
> after period of inactivity, when it goes into power saving mode
>
> Instead: brightness is dimmed after a few seconds
>
> As stated in title, screen brighness adjusts itself constantly: When
> adjusting brightness manualy, Galaxy Nexus device (maguro) is often dimmed
> immedeatly to seemingly some kind of default setting.
> Usualy, this bug happens within seconds after the brightness is set
> manualy. Sometimes though, it happens later at (apparently) random moments.
> On rare occasions, it doesnt happen at all.
> On every occasion however, the slider for manual setting stays where it
> is.
>
> At first, I was thinking it was triggered by an overzealous proximity
> sensor (which however works perfectly on android). Now I am leaning
> towards some sort of default setting or automated brightness. Judging
> from earlier posts on xda and LP, it seems there was such a feature at
> some stage in the beta. is there some kind of automatic brightness
> process at work, that overides the manual, but which has no interface?
>
> content of media-info:
> Ubuntu 13.10 - armhf (20131017)
>
> mat@Lapbuntu:~$ adb shell getprop ro.cm.device
> maguro
>
> To manage notifications about this bug go to:
> https://bugs.launchpad.net/powerd/+bug/1247694/+subscriptions
>

[Pat McGowan (pat-mcgowan)]

autobrightness control provided