From: Hans Verkuil <hans.verk...@cisco.com> The poll specification mentioned that it would return POLLERR if no buffers are queued. This makes no sense since the buffer queue can become empty during capturing and you want poll to wait until another thread queues up a new buffer and not to return POLLERR.
In the case where STREAMON is called without any buffers queued, the STREAMON ioctl will already check if enough buffers have been queued and return an error if that's not the case. This is driver dependent, some drivers require that buffers are queued, others don't. The poll() function certainly shouldn't check for this. Just drop the part about POLLERR being returned if QBUF wasn't called. Signed-off-by: Hans Verkuil <hans.verk...@cisco.com> --- Documentation/DocBook/media/v4l/func-poll.xml | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/Documentation/DocBook/media/v4l/func-poll.xml b/Documentation/DocBook/media/v4l/func-poll.xml index 85cad8b..2f91ca6 100644 --- a/Documentation/DocBook/media/v4l/func-poll.xml +++ b/Documentation/DocBook/media/v4l/func-poll.xml @@ -44,7 +44,7 @@ Capture devices set the <constant>POLLIN</constant> and flags. When the function timed out it returns a value of zero, on failure it returns <returnvalue>-1</returnvalue> and the <varname>errno</varname> variable is set appropriately. When the -application did not call &VIDIOC-QBUF; or &VIDIOC-STREAMON; yet the +application did not call &VIDIOC-STREAMON; the <function>poll()</function> function succeeds, but sets the <constant>POLLERR</constant> flag in the <structfield>revents</structfield> field.</para> -- 2.1.0 -- To unsubscribe from this list: send the line "unsubscribe linux-media" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
