[Suspend] unable to suspend, just stay black screen after wake up by power button from suspend

[regina_kim]

kernel : 20080903
rootfs : 20080911

Description : unable to suspend, just stay black screen after wake up by power button from suspend

step+current result :

1.set suspend time (10, 30, 60 sec)
2.press power button to wakes it up when it goes into suspend
3.wait until goes to suspend

----> but it just goes black screen

expected result : it should go to suspend.

[wendy_hung]

relate bug #1992, thanks for thepizzaking help us to get the log.

Let me discrib this bug more...
this bug means first time you set suspend time you'll have suspend time, but once you wake it up by power button, the second suspend time will fail (become blank time) you can click the screen to wake it up. So if this time you press the power button try to wake it up, actually is bring it to suspend time(use power button to suspend).
After second suspend (blank time) it still will go into suspend (third suspend) than this time you'll have really suspend time....

Hope this is clear enough. :)

[andy]

There's one thing extra about description that would help a lot, "black screen" or "blank screen" is very hard to know exactly what it means.

What we need to know is if the backlight is on or not. If the screen shows all black pixels with the backlight on, you can still see some light coming through if you take the device to a dark place. If the backlight is off though, it will be completely black all the time. Those two kinds of "black screen" are very different for us.

[h.koenig]

this sounds very familar to me -- see bug #1985.

at least in my case it looks like the backlit is off:

root@om-gta02:~# head /sys/devices/platform/s3c2440-i2c/i2c-adapter/i2c-0/0-0073/backlight/pcf50633-bl/*bright*
==> /sys/devices/platform/s3c2440-i2c/i2c-adapter/i2c-0/0-0073/backlight/pcf50633-bl/actual_brightness <==
0

==> /sys/devices/platform/s3c2440-i2c/i2c-adapter/i2c-0/0-0073/backlight/pcf50633-bl/brightness <==
63

==> /sys/devices/platform/s3c2440-i2c/i2c-adapter/i2c-0/0-0073/backlight/pcf50633-bl/max_brightness <==
63

[wendy_hung]

Hey Andy :)
thanks for your notice, I checked with commend line and it show up this:
root@om-gta02:~# cat /sys/class/backlight/pcf50633-bl/brightness
63

So I think the backlight is on...

[h.koenig]

Replying to wendy_hung:

Hey Andy :)
thanks for your notice, I checked with commend line and it show up this:
root@om-gta02:~# cat /sys/class/backlight/pcf50633-bl/brightness
63

So I think the backlight is on...

you have to check actual_brightness (see my last comment)...

[wendy_hung]

Tested with the base image, still sometimes happen like that.
Had shown this to Matt.

Tested day:2008.10.07
sorry already updated so can't attach a opkg list_installed...

Will keep track on this bug. :)

[wendy_hung]

test date:2008.10.31
update date:2008.10.29
Installed_list:as attach

Test with this testing image, it doesn't happen with this problem, but i would like to double check that. Close this one later.

[wendy_hung]

sorry, don't know why milestone will be delete....

[john_lee]

I will add similiar bugs here so it's easier to track.

[jeremy]

Thanks Wendy's test and explanation, it sounds it's goes to Blank, but not going to Suspend. And the user will misunderstand it should have already suspended cause the screen is black. Hopefully there will be a logread log for this issue cause #1992 I think is for another issue that is suspending happens right after the resume manually by pressing the power button.

[andy]

Is this problem still seen with recent 2.6.29 kernels?

[wendy_hung]

Tested with Paroli image doesn't have the Auto suspend function, but use the Power button to suspend/resume won't have this problem so far.