[RFC PATCH] v4l2-ctrls: fix NEXT_COMPOUND support

[Hans Verkuil <hverkuil@xs4all.nl>]

Ricardo reported a problem in v4l2-compliance if an integer control was used in
an array. It turned out to be a problem in the implementation of NEXT_COMPOUND
that didn't match arrays as being compound controls.

I also did some DocBook updates. The final version of this patch will split off
the docbook changes in a separate patch (or patches).

Ricardo, can you test this?

In order to be able to use integer controls in an array we also need a new field in
the union in struct v4l2_ext_control: __s32 __user *p_s32.

Ricardo, please test this thoroughly. I've never tested INTEGER arrays before, so
I'm not sure if there are no hidden surprises somewhere.

Regards,

	Hans

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Reported-by: Ricardo Ribalda Delgado <ricardo.ribalda@gmail.com>

diff --git a/Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml b/Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml
index c5bdbfc..842536a 100644
--- a/Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml
+++ b/Documentation/DocBook/media/v4l/vidioc-g-ext-ctrls.xml
@@ -200,6 +200,13 @@ Valid if this control is of type <constant>V4L2_CTRL_TYPE_U16</constant>.</entry
 	  </row>
 	  <row>
 	    <entry></entry>
+	    <entry>__u32 *</entry>
+	    <entry><structfield>p_u32</structfield></entry>
+	    <entry>A pointer to a matrix control of unsigned 32-bit values.
+Valid if this control is of type <constant>V4L2_CTRL_TYPE_U32</constant>.</entry>
+	  </row>
+	  <row>
+	    <entry></entry>
 	    <entry>void *</entry>
 	    <entry><structfield>ptr</structfield></entry>
 	    <entry>A pointer to a compound type which can be an N-dimensional array and/or a
diff --git a/Documentation/DocBook/media/v4l/vidioc-queryctrl.xml b/Documentation/DocBook/media/v4l/vidioc-queryctrl.xml
index 6ec39c6..8246b30 100644
--- a/Documentation/DocBook/media/v4l/vidioc-queryctrl.xml
+++ b/Documentation/DocBook/media/v4l/vidioc-queryctrl.xml
@@ -101,8 +101,9 @@ prematurely end the enumeration).</para></footnote></para>
 next supported non-compound control, or <errorcode>EINVAL</errorcode>
 if there is none. In addition, the <constant>V4L2_CTRL_FLAG_NEXT_COMPOUND</constant>
 flag can be specified to enumerate all compound controls (i.e. controls
-with type &ge; <constant>V4L2_CTRL_COMPOUND_TYPES</constant>). Specify both
-<constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant> and
+with type &ge; <constant>V4L2_CTRL_COMPOUND_TYPES</constant> and/or array
+control, in other words controls that contain more than one value).i
+Specify both <constant>V4L2_CTRL_FLAG_NEXT_CTRL</constant> and
 <constant>V4L2_CTRL_FLAG_NEXT_COMPOUND</constant> in order to enumerate
 all controls, compound or not. Drivers which do not support these flags yet
 always return <errorcode>EINVAL</errorcode>.</para>
@@ -422,7 +423,7 @@ the array to zero.</entry>
 	    <entry>any</entry>
 	    <entry>An integer-valued control ranging from minimum to
 maximum inclusive. The step value indicates the increment between
-values which are actually different on the hardware.</entry>
+values.</entry>
 	  </row>
 	  <row>
 	    <entry><constant>V4L2_CTRL_TYPE_BOOLEAN</constant></entry>
@@ -518,7 +519,7 @@ Older drivers which do not support this feature return an
 	    <entry>any</entry>
 	    <entry>An unsigned 8-bit valued control ranging from minimum to
 maximum inclusive. The step value indicates the increment between
-values which are actually different on the hardware.
+values.
 </entry>
 	  </row>
 	  <row>
@@ -528,7 +529,17 @@ values which are actually different on the hardware.
 	    <entry>any</entry>
 	    <entry>An unsigned 16-bit valued control ranging from minimum to
 maximum inclusive. The step value indicates the increment between
-values which are actually different on the hardware.
+values.
+</entry>
+	  </row>
+	  <row>
+	    <entry><constant>V4L2_CTRL_TYPE_U32</constant></entry>
+	    <entry>any</entry>
+	    <entry>any</entry>
+	    <entry>any</entry>
+	    <entry>An unsigned 32-bit valued control ranging from minimum to
+maximum inclusive. The step value indicates the increment between
+values.
 </entry>
 	  </row>
 	</tbody>
diff --git a/drivers/media/v4l2-core/v4l2-ctrls.c b/drivers/media/v4l2-core/v4l2-ctrls.c
index b6b7dcc..d5de70e 100644
--- a/drivers/media/v4l2-core/v4l2-ctrls.c
+++ b/drivers/media/v4l2-core/v4l2-ctrls.c
@@ -2498,7 +2498,7 @@ int v4l2_query_ext_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_query_ext_ctr
 			/* We found a control with the given ID, so just get
 			   the next valid one in the list. */
 			list_for_each_entry_continue(ref, &hdl->ctrl_refs, node) {
-				is_compound =
+				is_compound = ref->ctrl->is_array ||
 					ref->ctrl->type >= V4L2_CTRL_COMPOUND_TYPES;
 				if (id < ref->ctrl->id &&
 				    (is_compound & mask) == match)
@@ -2512,7 +2512,7 @@ int v4l2_query_ext_ctrl(struct v4l2_ctrl_handler *hdl, struct v4l2_query_ext_ctr
 			   is one, otherwise the first 'if' above would have
 			   been true. */
 			list_for_each_entry(ref, &hdl->ctrl_refs, node) {
-				is_compound =
+				is_compound = ref->ctrl->is_array ||
 					ref->ctrl->type >= V4L2_CTRL_COMPOUND_TYPES;
 				if (id < ref->ctrl->id &&
 				    (is_compound & mask) == match)