935391 - Better light sensor behavior to reduce flicker

Status: RESOLVED FIXED

(Firefox OS Graveyard :: Gaia::System, defect)

Description

[RaymondSu]

User Agent: Mozilla/5.0 (Windows NT 6.2; WOW64) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/30.0.1599.101 Safari/537.36

Steps to reproduce:

Clone bug from bug 923031 for public discussion


Actual results:

The light sensor behavior on Alcatel OnetouchFire and Flatflish looks too sensitive.
User may fell the response of screen brightness changing too annoying.  
The bigger screen the worse feeling.  Flatfish is the worst case.


Expected results:

Expected to have better behavior for light sensor handling.

Similar bugs on other platform : 805902 ;  819744...

Comment 1

[RaymondSu]

Attachment: 0001-adjust-the-brightness-value-at-a-time.patch

Comment 2

[RaymondSu]

That quote from Sam's comment in bug 923031:
0001-adjust-the-brightness-value-at-a-time.patch

The value of brightness is too sensitive which makes the screen might go dim or bright too frequent.
After changing the the value of BRIGHTNESS_ADJUST_STEP from 0.04 to 0.01,the status is acceptable.

Note: In Android, it happens at DisplayPowerController.java. However, I have no idea about why I can still find this .java in the framework in b2g source.

Comment 3

[RaymondSu]

Quote from Fred Lin:
Sam, 
change BRIGHTNESS_ADJUST_STEP only affect the moving time between current brightness to target brightness, but not solve the unstability 

I have a quick patch that delay the light adjustment certain time, then compare with current brightness to avoid immediate jitter

https://github.com/mozilla-b2g/gaia/pull/12950

You can apply it on device and see if it's more likely your expectation.

Comment 4

[RaymondSu]

Thanks Fred. I will give it a try later.
The way that Android takes to deal with the auto_brightness policy could be a good reference.
The followings are some differences in Android compared to FxOS.

1. Enabling Twilight adjustment
   - To expand the dynamic range of auto-brightness
     when it is especially dark outside.  The light sensor tends to perform
     poorly at low light levels so we compensate for it by making an
     assumption about the environment.

2. Setting two different hysteresis thresholds to debounce the light sensor when adapting to brighter or darker
   environemtns.
   -In these two different constants, the system will get the debounce time. 
    Hence, the ambient light value will be adjusted accordingly.

3. Apply spline adjustment. 
   - The auto-brightness spline adjustment. The brightness value have been scaled to a range of 0 . . 1.

There are much more detail information in these major functions. Please refer to the source in Android.

Comment 5

[Tim Guan-tin Chien [:timdream] (please needinfo)]

This bug is not specific to flatfish so we should push for a fix in Mozilla code base.

Comment 6

[Tim Guan-tin Chien [:timdream] (please needinfo)]

Sam, are you the author of attachment 827857 [details] [diff] [review]? I think we could land this patch. Please complete the Github patch submission flow (set reviewer to me) and we will include this patch into the main Mozilla open source codebase. Thanks.

https://developer.mozilla.org/en-US/Firefox_OS/Platform/Gaia/Hacking#Submitting_a_patch

Comment 7

[Sam Lin[:neopleo]]

Yes, I will complete the submission flow and set Tim as a reviewer.

Comment 8

[Tim Guan-tin Chien [:timdream] (please needinfo)]

Triage: not taking features for v1.3 at this point even if it's just a one line change.

I will ask for approval when the patch landed on master.

Comment 9

[Tim Guan-tin Chien [:timdream] (please needinfo)]

-'ing per comment above.

Comment 10

[Sam Lin[:neopleo]]

Attachment: the better light sensor behavior

Comment 11

[Sam Lin[:neopleo]]

Hi Tim, I have submitted the patch and set a reviewer to you for this patch.

Comment 12

[[e-mail]]

Hi Sam, please create a pull request instead of diff, and remove the commented code, thanks.

Comment 13

[Tim Guan-tin Chien [:timdream] (please needinfo)]

Comment on attachment 8350994 [details]
the better light sensor behavior

Please amend the patch and submit a pull request for master from this branch. Thanks!

Comment 14

[Sam Lin[:neopleo]]

Attachment: Change the value for adjusting of the brightness at a time.

Comment 15

[Sam Lin[:neopleo]]

Thanks, I have remove the commented code and done the pull request.

Comment 16

[Tim Guan-tin Chien [:timdream] (please needinfo)]

Comment on attachment 8351008 [details]
Change the value for adjusting of the brightness at a time.

You mean https://github.com/mozilla-b2g/gaia/pull/14919

We usually require trivial commits to be squashed into one commit before merging. To save us some time I am going to squash and merge this for you later today.

Comment 17

[Tim Guan-tin Chien [:timdream] (please needinfo)]

master: 7ccd4a9acec6dc490bb53f43c05b293cfe017eb4