linux/drivers/gpu
Zhao Yakui b16d9acbdb drm: disable all the possible outputs/crtcs before entering KMS mode
Sometimes we will use a crtc for integerated LVDS, which is different with
that assigned by BIOS. If we want to get flicker-free transitions,
then we could read out the current state for it and set our current state
accordingly.

But it is true that if we aren't reading current state out, we do need
to turn everything off before modesetting.  Otherwise the clocks can get very
angry and we get things worse than a flicker at boot.
In fact we also do the similar thing in UMS mode. We will disable all the
possible outputs/crtcs for the first modesetting.

So we disable all the possible outputs/crtcs before entering the KMS mode.
Before we configure connector/encoder/crtc, the function of
drm_helper_disable_unused_function can disable all the possible outputs/crtcs.

Signed-off-by: Zhao Yakui <yakui.zhao@intel.com>
Reviewed-by: Eric Anholt <eric@anholt.net>
Reviewed-by: Rafal Milecki <zajec5@gmail.com>
Signed-off-by: Dave Airlie <airlied@redhat.com>
2009-12-09 13:28:07 +10:00
..
drm drm: disable all the possible outputs/crtcs before entering KMS mode 2009-12-09 13:28:07 +10:00
vga PCI/vgaarb: cleanup some warnings + cleanup some comments. 2009-09-09 13:29:41 -07:00
Makefile PCI/GPU: implement VGA arbitration on Linux 2009-09-09 13:29:36 -07:00