GraphicsV 4 (changes)
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GraphicsV
» GraphicsV 4
Graphics Vector (42)
| Entry | |
|---|---|
| R0 | 0: Unblank display |
| 1: Blank display | |
| R1 | DPMS State when blanking display |
| R4 | Bits 0-15: 4 (reason code) |
| Bits 16-23: Head number | |
| Bits 24-31: Driver number |
| Exit | |
|---|---|
| R4 | 0 |
| - | All other registers preserved |
Use
The kernel issues this call in order to instruct the display driver to enable or disable the display, putting the display into the indicated DPMS state if possible. The appropriate driver should respond by performing the requested action and setting R4 to 0 to claim the call.
Notes
When the display is blanked blanked, it’s permissible for drivers to take additional steps to reduce power consumption, providing that they do not conflict with the intendedDPMS state of the monitor. E.g. it’s reasonable to expect a driver to disable video DMA or hide any visible overlays. For digital interfaces it may be possible to gate the delivery of the pixel clock, and when entering DPMS state 3 it may be possible to power-down the GPU completely.
When the display is blanked blanked, there is no requirement for the driver to continue to deliver VSync interrupts.
See also
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