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-rw-r--r--Documentation/DocBook/drm.tmpl39
1 files changed, 25 insertions, 14 deletions
diff --git a/Documentation/DocBook/drm.tmpl b/Documentation/DocBook/drm.tmpl
index da011f2..457d56a 100644
--- a/Documentation/DocBook/drm.tmpl
+++ b/Documentation/DocBook/drm.tmpl
@@ -619,23 +619,34 @@ void intel_crt_init(struct drm_device *dev)
<title>VBlank event handling</title>
<para>
The DRM core exposes two vertical blank related ioctls:
- DRM_IOCTL_WAIT_VBLANK and DRM_IOCTL_MODESET_CTL.
+ <variablelist>
+ <varlistentry>
+ <term>DRM_IOCTL_WAIT_VBLANK</term>
+ <listitem>
+ <para>
+ This takes a struct drm_wait_vblank structure as its argument,
+ and it is used to block or request a signal when a specified
+ vblank event occurs.
+ </para>
+ </listitem>
+ </varlistentry>
+ <varlistentry>
+ <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).
+ </para>
+ </listitem>
+ </varlistentry>
+ </variablelist>
<!--!Edrivers/char/drm/drm_irq.c-->
</para>
<para>
- DRM_IOCTL_WAIT_VBLANK takes a struct drm_wait_vblank structure
- as its argument, and is used to block or request a signal when a
- specified vblank event occurs.
- </para>
- <para>
- DRM_IOCTL_MODESET_CTL 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).
- </para>
- <para>
To support the functions above, the DRM core provides several
helper functions for tracking vertical blank counters, and
requires drivers to provide several callbacks:
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