[media] DocBook: in non-blocking mode return EAGAIN in hwseek

VIDIOC_S_HW_FREQ_SEEK should return EAGAIN when called in non-blocking
mode. This might change in the future if we add support for this in the
future, but right now this is not supported.

Signed-off-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 10 insertions, 0 deletions

diff --git a/Documentation/DocBook/media/v4l/vidioc-s-hw-freq-seek.xml b/Documentation/DocBook/media/v4l/vidioc-s-hw-freq-seek.xml
index 3dd1bec6d3c7..5b379e752194 100644
--- a/Documentation/DocBook/media/v4l/vidioc-s-hw-freq-seek.xml
+++ b/Documentation/DocBook/media/v4l/vidioc-s-hw-freq-seek.xml
@@ -75,6 +75,9 @@ seek is started.</para>
 
     <para>This ioctl is supported if the <constant>V4L2_CAP_HW_FREQ_SEEK</constant> capability is set.</para>
 
+    <para>If this ioctl is called from a non-blocking filehandle, then &EAGAIN; is
+    returned and no seek takes place.</para>
+
     <table pgwide="1" frame="none" id="v4l2-hw-freq-seek">
       <title>struct <structname>v4l2_hw_freq_seek</structname></title>
       <tgroup cols="3">
@@ -158,6 +161,13 @@ fields is wrong.</para>
         </listitem>
       </varlistentry>
       <varlistentry>
+        <term><errorcode>EAGAIN</errorcode></term>
+        <listitem>
+          <para>Attempted to call <constant>VIDIOC_S_HW_FREQ_SEEK</constant>
+          with the filehandle in non-blocking mode.</para>
+        </listitem>
+      </varlistentry>
+      <varlistentry>
         <term><errorcode>ENODATA</errorcode></term>
         <listitem>
           <para>The hardware seek found no channels.</para>