From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-10.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,USER_AGENT_GIT autolearn=ham autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id A0941C4CEC4 for ; Sun, 22 Sep 2019 19:39:16 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 783D720644 for ; Sun, 22 Sep 2019 19:39:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569181156; bh=YRxLwZTD2kyRklJzSvxmQ6ggHmLqbT6T6h2wJ2/43pQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:List-ID:From; b=PQc9uwgDv8cj2GMHJ5/g6OsKa9QFqUI0hUQDBFPyw2h/KKsOZEhn5NUAxuYYzHrFu BNrHJK3wggdy3dGwJhk0Fjkk9W2JjEWI50BTPosPKYaLkFwgyTtvQQAkNA5WOjQbF/ Qu9pibzs+eoMbQ0AN4Hb3/f1a2+c5qZ0Cv1fbVVE= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2388982AbfIVSpG (ORCPT ); Sun, 22 Sep 2019 14:45:06 -0400 Received: from mail.kernel.org ([198.145.29.99]:40628 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2388919AbfIVSpD (ORCPT ); Sun, 22 Sep 2019 14:45:03 -0400 Received: from sasha-vm.mshome.net (c-73-47-72-35.hsd1.nh.comcast.net [73.47.72.35]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 19AAE21D7F; Sun, 22 Sep 2019 18:45:02 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1569177902; bh=YRxLwZTD2kyRklJzSvxmQ6ggHmLqbT6T6h2wJ2/43pQ=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=gJzkjo2BqLxh0Re+Tnf+rybnnci1L/xMY/gVeU1ddAJkgLW7ykm2QQ30ith0CDhP3 CNgg+orYejNHef5kT0+eTtNG3ItV8yikUUpAXYSQKgnITHd0wL/UaeBDLfTF3xTA4V 8leYdk6GaxP7Y5NoXj3ONgES/xITtg65lgJeJUyI= From: Sasha Levin To: linux-kernel@vger.kernel.org, stable@vger.kernel.org Cc: Michael Tretter , Hans Verkuil , Mauro Carvalho Chehab , Sasha Levin , linux-media@vger.kernel.org Subject: [PATCH AUTOSEL 5.3 020/203] media: vb2: reorder checks in vb2_poll() Date: Sun, 22 Sep 2019 14:40:46 -0400 Message-Id: <20190922184350.30563-20-sashal@kernel.org> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190922184350.30563-1-sashal@kernel.org> References: <20190922184350.30563-1-sashal@kernel.org> MIME-Version: 1.0 X-stable: review X-Patchwork-Hint: Ignore Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Michael Tretter [ Upstream commit 8d86a15649957c182e90fa2b1267c16699bc12f1 ] When reaching the end of stream, V4L2 clients may expect the V4L2_EOS_EVENT before being able to dequeue the last buffer, which has the V4L2_BUF_FLAG_LAST flag set. If the vb2_poll() function first checks for events and afterwards if buffers are available, a driver can queue the V4L2_EOS_EVENT event and return the buffer after the check for events but before the check for buffers. This causes vb2_poll() to signal that the buffer with V4L2_BUF_FLAG_LAST can be read without the V4L2_EOS_EVENT being available. First, check for available buffers and afterwards for events to ensure that if vb2_poll() signals POLLIN | POLLRDNORM for the V4L2_BUF_FLAG_LAST buffer, it also signals POLLPRI for the V4L2_EOS_EVENT. Signed-off-by: Michael Tretter Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab Signed-off-by: Sasha Levin --- drivers/media/common/videobuf2/videobuf2-v4l2.c | 8 +++++--- 1 file changed, 5 insertions(+), 3 deletions(-) diff --git a/drivers/media/common/videobuf2/videobuf2-v4l2.c b/drivers/media/common/videobuf2/videobuf2-v4l2.c index 40d76eb4c2fe7..5a9ba3846f0a5 100644 --- a/drivers/media/common/videobuf2/videobuf2-v4l2.c +++ b/drivers/media/common/videobuf2/videobuf2-v4l2.c @@ -872,17 +872,19 @@ EXPORT_SYMBOL_GPL(vb2_queue_release); __poll_t vb2_poll(struct vb2_queue *q, struct file *file, poll_table *wait) { struct video_device *vfd = video_devdata(file); - __poll_t res = 0; + __poll_t res; + + res = vb2_core_poll(q, file, wait); if (test_bit(V4L2_FL_USES_V4L2_FH, &vfd->flags)) { struct v4l2_fh *fh = file->private_data; poll_wait(file, &fh->wait, wait); if (v4l2_event_pending(fh)) - res = EPOLLPRI; + res |= EPOLLPRI; } - return res | vb2_core_poll(q, file, wait); + return res; } EXPORT_SYMBOL_GPL(vb2_poll); -- 2.20.1