於 四，2012-07-26 於 14:58 +0200，Luca Tettamanti 提到：
- again ACPI video module gets the nodification (in this case ACPI_VIDEO_NOTIFY_PROBE), re-enumerated and send KEY_SWITCHVIDEOMODE
- KDE seems this and muck with the screen configuration :(
- meanwhile the brightness notification is propagated, the
hypothetical radeon driver does its magic to adjust the screen.
My first idea would be to make ACPI_VIDEO_NOTIFY_PROBE also call to the acpi notifier chain, and allow the handlers to veto the key press (like it's done for ACPI_VIDEO_NOTIFY_SWITCH).
I welcome this approach!
On some ATI machine's DSDT also issue ACPI_VIDEO_NOTIFY_PROBE when AC-power unplug, because BIOS want to nodify video driver do some power saving stuff. It causes KEY_SWITCHVIDEOMODE issued by acpi/video driver when AC-power unplug.
At least acpi/video driver need to know this 0x81 event is filed by BIOS to radeon-acpi for notify but not do video mode switch. That means the radeon drm need take the video switch responsibility.
Thanks a lot! Joey Lee