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authorGrant Likely <grant.likely@secretlab.ca>2010-05-22 00:36:56 -0600
committerGrant Likely <grant.likely@secretlab.ca>2010-05-22 00:36:56 -0600
commitcf9b59e9d3e008591d1f54830f570982bb307a0d (patch)
tree113478ce8fd8c832ba726ffdf59b82cb46356476 /Documentation/DocBook/v4l/vidioc-qbuf.xml
parent44504b2bebf8b5823c59484e73096a7d6574471d (diff)
parentf4b87dee923342505e1ddba8d34ce9de33e75050 (diff)
downloadop-kernel-dev-cf9b59e9d3e008591d1f54830f570982bb307a0d.zip
op-kernel-dev-cf9b59e9d3e008591d1f54830f570982bb307a0d.tar.gz
Merge remote branch 'origin' into secretlab/next-devicetree
Merging in current state of Linus' tree to deal with merge conflicts and build failures in vio.c after merge. Conflicts: drivers/i2c/busses/i2c-cpm.c drivers/i2c/busses/i2c-mpc.c drivers/net/gianfar.c Also fixed up one line in arch/powerpc/kernel/vio.c to use the correct node pointer. Signed-off-by: Grant Likely <grant.likely@secretlab.ca>
Diffstat (limited to 'Documentation/DocBook/v4l/vidioc-qbuf.xml')
-rw-r--r--Documentation/DocBook/v4l/vidioc-qbuf.xml14
1 files changed, 12 insertions, 2 deletions
diff --git a/Documentation/DocBook/v4l/vidioc-qbuf.xml b/Documentation/DocBook/v4l/vidioc-qbuf.xml
index b843bd7..ab691eb 100644
--- a/Documentation/DocBook/v4l/vidioc-qbuf.xml
+++ b/Documentation/DocBook/v4l/vidioc-qbuf.xml
@@ -111,7 +111,11 @@ from the driver's outgoing queue. They just set the
and <structfield>reserved</structfield>
fields of a &v4l2-buffer; as above, when <constant>VIDIOC_DQBUF</constant>
is called with a pointer to this structure the driver fills the
-remaining fields or returns an error code.</para>
+remaining fields or returns an error code. The driver may also set
+<constant>V4L2_BUF_FLAG_ERROR</constant> in the <structfield>flags</structfield>
+field. It indicates a non-critical (recoverable) streaming error. In such case
+the application may continue as normal, but should be aware that data in the
+dequeued buffer might be corrupted.</para>
<para>By default <constant>VIDIOC_DQBUF</constant> blocks when no
buffer is in the outgoing queue. When the
@@ -158,7 +162,13 @@ enqueue a user pointer buffer.</para>
<para><constant>VIDIOC_DQBUF</constant> failed due to an
internal error. Can also indicate temporary problems like signal
loss. Note the driver might dequeue an (empty) buffer despite
-returning an error, or even stop capturing.</para>
+returning an error, or even stop capturing. Reusing such buffer may be unsafe
+though and its details (e.g. <structfield>index</structfield>) may not be
+returned either. It is recommended that drivers indicate recoverable errors
+by setting the <constant>V4L2_BUF_FLAG_ERROR</constant> and returning 0 instead.
+In that case the application should be able to safely reuse the buffer and
+continue streaming.
+ </para>
</listitem>
</varlistentry>
</variablelist>
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