#16341: Screen Preferences - bright slider don't work on Intel GMA (GM45)
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Reporter: un_spacyar | Owner: pulkomandy
Type: bug | Status: new
Priority: normal | Milestone: Unscheduled
Component: Drivers/Graphics/intel_extreme/g45 | Version: R1/beta2
Resolution: | Keywords:
Blocked By: | Blocking:
Platform: All |
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Comment (by pulkomandy):
Thanks. So, the good news is I have a machine with the same problem here
(interestingly the hardware shortcut to change the brightness is working).
The bad news is I didn't find yet where the brightness is stored in this
case.
For my own reference: reproducible on Dell Inspiron 1525 (GM965).
The meaning of the register values (probably only for my own reference as
well):
- Backlight control PLL enabled, legacy mode enabled (so backlight can
also be set from a register directly in PCI), backlight control on pipe B
- Both duty cycle and period are set to 0, which makes no sense when the
PLL is enabled
- Trying to change the register values does not have any effect.
- I did not try changing the value using the legacy register, which is not
as easily accessible (it is at addresses F4-F7 in the PCI registers, and
writing the first byte with a value between 0 and 255 should work if it is
being used in some way).
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Ticket URL: <https://dev.haiku-os.org/ticket/16341#comment:4>
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