From patchwork Thu Jun 27 12:44:32 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Tretter X-Patchwork-Id: 11019631 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 9D3321398 for ; Thu, 27 Jun 2019 12:44:39 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 8EC3328A73 for ; Thu, 27 Jun 2019 12:44:39 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 8365628A7D; Thu, 27 Jun 2019 12:44:39 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 483E828A77 for ; Thu, 27 Jun 2019 12:44:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726669AbfF0Mog (ORCPT ); Thu, 27 Jun 2019 08:44:36 -0400 Received: from metis.ext.pengutronix.de ([85.220.165.71]:55857 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726542AbfF0Mog (ORCPT ); Thu, 27 Jun 2019 08:44:36 -0400 Received: from dude02.hi.pengutronix.de ([2001:67c:670:100:1d::28] helo=dude02.lab.pengutronix.de) by metis.ext.pengutronix.de with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1hgTlS-0002h2-W6; Thu, 27 Jun 2019 14:44:34 +0200 Received: from mtr by dude02.lab.pengutronix.de with local (Exim 4.89) (envelope-from ) id 1hgTlS-00086N-Eh; Thu, 27 Jun 2019 14:44:34 +0200 From: Michael Tretter To: linux-media@vger.kernel.org Cc: kernel@pengutronix.de, pawel@osciak.com, hverkuil-cisco@xs4all.nl, mchehab@kernel.org, Michael Tretter Subject: [PATCH v2 1/2] media: vb2: reorder checks in vb2_poll() Date: Thu, 27 Jun 2019 14:44:32 +0200 Message-Id: <20190627124433.31051-2-m.tretter@pengutronix.de> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190627124433.31051-1-m.tretter@pengutronix.de> References: <20190627124433.31051-1-m.tretter@pengutronix.de> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::28 X-SA-Exim-Mail-From: mtr@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-media@vger.kernel.org Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP 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 --- v1 -> v2: - none --- 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 40d76eb4c2fe..5a9ba3846f0a 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); From patchwork Thu Jun 27 12:44:33 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Michael Tretter X-Patchwork-Id: 11019629 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id 7BAB91398 for ; Thu, 27 Jun 2019 12:44:38 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 6D69828A73 for ; Thu, 27 Jun 2019 12:44:38 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 61C7C28A7E; Thu, 27 Jun 2019 12:44:38 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-7.9 required=2.0 tests=BAYES_00,MAILING_LIST_MULTI, RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id AF22D28A7D for ; Thu, 27 Jun 2019 12:44:37 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726590AbfF0Mog (ORCPT ); Thu, 27 Jun 2019 08:44:36 -0400 Received: from metis.ext.pengutronix.de ([85.220.165.71]:60847 "EHLO metis.ext.pengutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726472AbfF0Mog (ORCPT ); Thu, 27 Jun 2019 08:44:36 -0400 Received: from dude02.hi.pengutronix.de ([2001:67c:670:100:1d::28] helo=dude02.lab.pengutronix.de) by metis.ext.pengutronix.de with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1hgTlS-0002h3-W6; Thu, 27 Jun 2019 14:44:34 +0200 Received: from mtr by dude02.lab.pengutronix.de with local (Exim 4.89) (envelope-from ) id 1hgTlS-00086Q-FC; Thu, 27 Jun 2019 14:44:34 +0200 From: Michael Tretter To: linux-media@vger.kernel.org Cc: kernel@pengutronix.de, pawel@osciak.com, hverkuil-cisco@xs4all.nl, mchehab@kernel.org, Michael Tretter Subject: [PATCH v2 2/2] media: v4l2-mem2mem: reorder checks in v4l2_m2m_poll() Date: Thu, 27 Jun 2019 14:44:33 +0200 Message-Id: <20190627124433.31051-3-m.tretter@pengutronix.de> X-Mailer: git-send-email 2.20.1 In-Reply-To: <20190627124433.31051-1-m.tretter@pengutronix.de> References: <20190627124433.31051-1-m.tretter@pengutronix.de> MIME-Version: 1.0 X-SA-Exim-Connect-IP: 2001:67c:670:100:1d::28 X-SA-Exim-Mail-From: mtr@pengutronix.de X-SA-Exim-Scanned: No (on metis.ext.pengutronix.de); SAEximRunCond expanded to false X-PTX-Original-Recipient: linux-media@vger.kernel.org Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP When reaching the end of stream, V4L2 m2m clients may expect the V4L2_EOS_EVENT. Although the V4L2_EOS_EVENT is deprecated behavior, drivers must signal that event before dequeuing the buffer that has the V4L2_BUF_FLAG_LAST flag set. If a driver queues the V4L2_EOS_EVENT event and returns the buffer after the check for events but before the check for buffers, vb2_m2m_poll() will signal that the buffer with V4L2_BUF_FLAG_LAST can be read but not that the V4L2_EOS_EVENT is available. Split the check for buffers into a separate function and check for available buffers before checking for events. This ensures that if vb2_m2m_poll() signals POLLIN | POLLRDNORM for the V4L2_BUF_FLAG_LAST buffer, it signals POLLPRI for the V4L2_EOS_EVENT, too. Signed-off-by: Michael Tretter --- v1 -> v2: - rename __v4l2_m2m_poll() to v4l2_m2m_poll_for_data() --- drivers/media/v4l2-core/v4l2-mem2mem.c | 47 +++++++++++++++----------- 1 file changed, 27 insertions(+), 20 deletions(-) diff --git a/drivers/media/v4l2-core/v4l2-mem2mem.c b/drivers/media/v4l2-core/v4l2-mem2mem.c index 4f5176702937..e21aa05245dc 100644 --- a/drivers/media/v4l2-core/v4l2-mem2mem.c +++ b/drivers/media/v4l2-core/v4l2-mem2mem.c @@ -603,11 +603,10 @@ int v4l2_m2m_streamoff(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, } EXPORT_SYMBOL_GPL(v4l2_m2m_streamoff); -__poll_t v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, - struct poll_table_struct *wait) +static __poll_t v4l2_m2m_poll_for_data(struct file *file, + struct v4l2_m2m_ctx *m2m_ctx, + struct poll_table_struct *wait) { - struct video_device *vfd = video_devdata(file); - __poll_t req_events = poll_requested_events(wait); struct vb2_queue *src_q, *dst_q; struct vb2_buffer *src_vb = NULL, *dst_vb = NULL; __poll_t rc = 0; @@ -619,16 +618,6 @@ __poll_t v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, poll_wait(file, &src_q->done_wq, wait); poll_wait(file, &dst_q->done_wq, 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)) - rc = EPOLLPRI; - if (!(req_events & (EPOLLOUT | EPOLLWRNORM | EPOLLIN | EPOLLRDNORM))) - return rc; - } - /* * There has to be at least one buffer queued on each queued_list, which * means either in driver already or waiting for driver to claim it @@ -637,10 +626,8 @@ __poll_t v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, if ((!src_q->streaming || src_q->error || list_empty(&src_q->queued_list)) && (!dst_q->streaming || dst_q->error || - list_empty(&dst_q->queued_list))) { - rc |= EPOLLERR; - goto end; - } + list_empty(&dst_q->queued_list))) + return EPOLLERR; spin_lock_irqsave(&dst_q->done_lock, flags); if (list_empty(&dst_q->done_list)) { @@ -650,7 +637,7 @@ __poll_t v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, */ if (dst_q->last_buffer_dequeued) { spin_unlock_irqrestore(&dst_q->done_lock, flags); - return rc | EPOLLIN | EPOLLRDNORM; + return EPOLLIN | EPOLLRDNORM; } } spin_unlock_irqrestore(&dst_q->done_lock, flags); @@ -673,7 +660,27 @@ __poll_t v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, rc |= EPOLLIN | EPOLLRDNORM; spin_unlock_irqrestore(&dst_q->done_lock, flags); -end: + return rc; +} + +__poll_t v4l2_m2m_poll(struct file *file, struct v4l2_m2m_ctx *m2m_ctx, + struct poll_table_struct *wait) +{ + struct video_device *vfd = video_devdata(file); + __poll_t req_events = poll_requested_events(wait); + __poll_t rc = 0; + + if (req_events & (EPOLLOUT | EPOLLWRNORM | EPOLLIN | EPOLLRDNORM)) + rc = v4l2_m2m_poll_for_data(file, m2m_ctx, 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)) + rc |= EPOLLPRI; + } + return rc; } EXPORT_SYMBOL_GPL(v4l2_m2m_poll);