Leftover from the old days of ums and should be used any longer. Since
commit 29935554b384b1b3a7377d6f0b03b21d18a61683 Author: Laurent Pinchart laurent.pinchart@ideasonboard.com Date: Wed May 30 00:58:09 2012 +0200
drm: Disallow DRM_IOCTL_MODESET_CTL for KMS drivers
it is a complete no-Op for kms drivers.
Cc: Laurent Pinchart laurent.pinchart@ideasonboard.com Signed-off-by: Daniel Vetter daniel.vetter@ffwll.ch --- Documentation/DocBook/drm.tmpl | 11 +++++------ 1 file changed, 5 insertions(+), 6 deletions(-)
diff --git a/Documentation/DocBook/drm.tmpl b/Documentation/DocBook/drm.tmpl index 83dd0b043c28..e37a77a72b8b 100644 --- a/Documentation/DocBook/drm.tmpl +++ b/Documentation/DocBook/drm.tmpl @@ -2861,12 +2861,11 @@ int num_ioctls;</synopsis> <term>DRM_IOCTL_MODESET_CTL</term> <listitem> <para> - This should be called by application level drivers before and - after mode setting, since on many devices the vertical blank - counter is reset at that time. Internally, the DRM snapshots - the last vblank count when the ioctl is called with the - _DRM_PRE_MODESET command, so that the counter won't go backwards - (which is dealt with when _DRM_POST_MODESET is used). + This was only used for user-mode-settind drivers around + modesetting changes to allow the kernel to update the vblank + interrupt after mode setting, since on many devices the vertical + blank. Modern drivers should not call this any more since with + kernel mode setting it is a no-Op. </para> </listitem> </varlistentry>