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-rw-r--r--Documentation/DocBook/drm.tmpl12
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>
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