Re: Turning backlight off on a wince device

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On May 13, 9:02 am, "Michel Verhagen (eMVP)" <mic...@xxxxxxxxxx>
wrote:
Are you sure the PM actually transitions states? Write a simple test
program that registers for power notifications
(RequestPowerNotifications with PBT_TRANSITION) and see if the PM is
actually transitioning states.

There may be something wrong with your registry settings (like you have
to put them betweeen ;HIVE BOOT SECTION tags for instance).

Also, enable all PM debug zones and check the debug output. The PM debug
output is abundant and will definitely help you pinpoint the problem. If
you still can't figure it out please post the debug output around the
state change.

Good luck,

Michel Verhagen, eMVP
Check out my blog:http://GuruCE.com/blog

  GuruCE Ltd.
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rashee...@xxxxxxxxx wrote:
I am trying to turn off backlight on my wince based device. The use
case is as follows:
After 10 secs of inactivity, userIdle state is reached. This state is
to be mapped to D4 (suspend) state of backlight driver. So that
backlight should be turned off after 10 secs of user inactivity.
The reg settings which i am using are:

IF SYSGEN_PM

; Turn the backlight off during UserIdle.

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Power\State
\UserIdle\{A32942B7-920C-486b-B0E692A702A99B35}]
 "BKL"=dword:4           ; D4  =>backlight off

[HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Power\Timeouts]
; @CESYSGEN IF PM_PM_DEFAULT_PDD
    "ACUserIdle"=dword:a         ; implies 10 seconds : Time after which
backlight will turn off

ENDIF

But on reaching userIdle state IOCTL_POWER_SET is not being called by
the power manager which requests the device state change.Due to it the
backlight is not getting turned off.

Can anybody please provide some suggestion for this problem...- Hide quoted text -

- Show quoted text -

Hi

Thanks for the suggestion. Actually we are using the same architecture
for turning off display. We are mapping the systemIdle state with
display driver's D4 state. This solution is working fine for display.
Also in case of backlight IOCTL_POWER_CAPABILITIES is being called so
support for D0 and D4 states is there. That means I am providing the
correct Iclass ie PMCLASS_GENERIC_DEVICE and AdvertiseInterface call
is also working fine. I somehow feel that the mapping between system
and device power states is not correct. Thats why there is no driver
state change when useridle state is reached. can you please throw some
light on this issue. Otherwise I am also trying to do what you
suggested
thnkz..!
.

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