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| author | Daniel Vetter <daniel.vetter@ffwll.ch> | 2014-05-08 13:39:19 (GMT) |
|---|---|---|
| committer | Daniel Vetter <daniel.vetter@ffwll.ch> | 2014-05-21 09:31:00 (GMT) |
| commit | 8edffbb933619d568ea98edd3b55ec7c30df9274 (patch) | |
| tree | 2f0214456eff61be5d4cc6b296da4f893d3360c5 /Documentation | |
| parent | add1d00823a820f8244c88407d7112d4a66e70c8 (diff) | |
| download | linux-8edffbb933619d568ea98edd3b55ec7c30df9274.tar.xz | |
drm/doc: Discourage usage of MODESET_CTL ioctl
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.
v2: Fix up mangled sentence spotted by Michel.
Cc: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Cc: Michel Dänzer <michel@daenzer.net>
Reviewed-by: Ville Syrjälä <ville.syrjala@linux.intel.com>
Signed-off-by: Daniel Vetter <daniel.vetter@ffwll.ch>
Diffstat (limited to 'Documentation')
| -rw-r--r-- | Documentation/DocBook/drm.tmpl | 12 |
1 files changed, 6 insertions, 6 deletions
diff --git a/Documentation/DocBook/drm.tmpl b/Documentation/DocBook/drm.tmpl index ec81c20..ad93c3e 100644 --- a/Documentation/DocBook/drm.tmpl +++ b/Documentation/DocBook/drm.tmpl @@ -2861,12 +2861,12 @@ 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 counter is reset to 0 at some point during modeset. Modern + drivers should not call this any more since with kernel mode + setting it is a no-op. </para> </listitem> </varlistentry> |