901809 - [B2G][Helix][Gaia]There is flash when automatically adjusting the screen brightness.

Status: RESOLVED INVALID

(Firefox OS Graveyard :: Gaia::System, defect, P2)

Description

[lecky]

User Agent: Mozilla/4.0 (compatible; MSIE 8.0; Windows NT 6.1; Trident/4.0; SLCC2; .NET CLR 2.0.50727; .NET CLR 3.5.30729; .NET CLR 3.0.30729; Media Center PC 6.0; aff-kingsoft-ciba; .NET4.0C; .NET4.0E)

Steps to reproduce:

1.Put the device under a light.
2.Block the window of light sensor.


Actual results:

The screen brightness automatically adjusted to a lower brightness.
But there is flash in the process of adjustment.


Expected results:

The process of adjustment should be smooth.Can not feel flashing.

If modify these constants in screen_manager.js, the flash will disappear.

  /*
   * When we change brightness we animate it smoothly.
   * This constant is the number of milliseconds between adjustments
   */
  BRIGHTNESS_ADJUST_INTERVAL: 10,

  /*
   * When brightening or dimming the screen, this is how much we adjust
   * the brightness value at a time.
   */
  BRIGHTNESS_ADJUST_STEP: 0.004,

Please help to check, thanks.

Comment 1

[Wayne Chang [:wchang]]

Marco, I think this somehow needs to be adjusted on OEM side, can you share some insights?

Comment 2

[Marco Chen [:mchen]]

Hi Lecky,

If you think this is correct for the Helix then it is welcome to contribute it here.

We will check the flash is coming from which part.
ex: unstable light sensor value or unstable backlight levels or...

Comment 3

[Marco Chen [:mchen]]

Hi Viral,

Could you help to check the reason of the unstable transition caused by light sensor? Thank.

Comment 4

[viral [:viralwang]]

in latest image (20130805), I didn't see the flash when auto backlight.
I check the data of light sensor looks smooth, I can see the range is 0-6 in my side.
backlight brightness also looks good to me should be no flash.
W/lights  (  160): LCD backlight current value =109
W/lights  (  160): LCD backlight current value =119
W/lights  (  160): LCD backlight current value =129
W/lights  (  160): LCD backlight current value =139
W/lights  (  160): LCD backlight current value =149
W/lights  (  160): LCD backlight current value =159
W/lights  (  160): LCD backlight current value =169
W/lights  (  160): LCD backlight current value =179
W/lights  (  160): LCD backlight current value =189
W/lights  (  160): LCD backlight current value =193
W/lights  (  160): LCD backlight current value =203
W/lights  (  160): LCD backlight current value =213
W/lights  (  160): LCD backlight current value =214
W/lights  (  160): LCD backlight current value =204
W/lights  (  160): LCD backlight current value =194
W/lights  (  160): LCD backlight current value =193
W/lights  (  160): LCD backlight current value =183
W/lights  (  160): LCD backlight current value =173

if the flash can be observe easily, may I have video to check the symptom?
Thank you.

Comment 5

[lecky]

Hi Viral, 

If adjust between level1(69) and level2(162), the flash will be observed easily.
The current delta is 10, it's too large, I think it's the cause of flash.

Please check, thanks!

Comment 6

[viral [:viralwang]]

Hi Lecky,

As our discussion, my suggestion will be changing following parameters in your side.

BRIGHTNESS_ADJUST_INTERVAL
BRIGHTNESS_ADJUST_STEP

Comment 7

[lecky]

OK, thank you!