[PATCH 06/12] drm/doc: Discourage usage of MODESET_CTL ioctl

Daniel Vetter
2014-05-14T18:51:08Z

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>


- 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.


</varlistentry>
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1.8.3.1