2 files changed, 13 insertions, 26 deletions

diff --git a/Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml b/Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml
index 6f1f9a629dc3..b17a7aac6997 100644
--- a/Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml
+++ b/Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml
@@ -183,7 +183,12 @@ applications must set the array to zero.</entry>
             <entry>__u32</entry>
             <entry><structfield>ctrl_class</structfield></entry>
             <entry>The control class to which all controls belong, see
-<xref linkend="ctrl-class" />.</entry>
+<xref linkend="ctrl-class" />. Drivers that use a kernel framework for handling
+controls will also accept a value of 0 here, meaning that the controls can
+belong to any control class. Whether drivers support this can be tested by setting
+<structfield>ctrl_class</structfield> to 0 and calling <constant>VIDIOC_TRY_EXT_CTRLS</constant>
+with a <structfield>count</structfield> of 0. If that succeeds, then the driver
+supports this feature.</entry>
           </row>
           <row>
             <entry>__u32</entry>
@@ -194,10 +199,13 @@ also be zero.</entry>
           <row>
             <entry>__u32</entry>
             <entry><structfield>error_idx</structfield></entry>
-            <entry>Set by the driver in case of an error. It is the
-index of the control causing the error or equal to 'count' when the
-error is not associated with a particular control. Undefined when the
-ioctl returns 0 (success).</entry>
+            <entry>Set by the driver in case of an error. If it is equal
+to <structfield>count</structfield>, then no actual changes were made to
+controls. In other words, the error was not associated with setting a particular
+control. If it is another value, then only the controls up to <structfield>error_idx-1</structfield>
+were modified and control <structfield>error_idx</structfield> is the one that
+caused the error. The <structfield>error_idx</structfield> value is undefined
+if the ioctl returned 0 (success).</entry>
           </row>
           <row>
             <entry>__u32</entry>
diff --git a/Documentation/video4linux/v4l2-controls.txt b/Documentation/video4linux/v4l2-controls.txt
index 26aa0573933e..e2492a9d1027 100644
--- a/Documentation/video4linux/v4l2-controls.txt
+++ b/Documentation/video4linux/v4l2-controls.txt
@@ -666,27 +666,6 @@ a control of this type whenever the first control belonging to a new control
 class is added.
 
 
-Differences from the Spec
-=========================
-
-There are a few places where the framework acts slightly differently from the
-V4L2 Specification. Those differences are described in this section. We will
-have to see whether we need to adjust the spec or not.
-
-1) It is no longer required to have all controls contained in a
-v4l2_ext_control array be from the same control class. The framework will be
-able to handle any type of control in the array. You need to set ctrl_class
-to 0 in order to enable this. If ctrl_class is non-zero, then it will still
-check that all controls belong to that control class.
-
-If you set ctrl_class to 0 and count to 0, then it will only return an error
-if there are no controls at all.
-
-2) Clarified the way error_idx works. For get and set it will be equal to
-count if nothing was done yet. If it is less than count then only the controls
-up to error_idx-1 were successfully applied.
-
-
 Proposals for Extensions
 ========================