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=-9.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, 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 81B95C04E87 for ; Sat, 18 May 2019 01:07:58 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 5DABF2189E for ; Sat, 18 May 2019 01:07:58 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728037AbfERBH5 (ORCPT ); Fri, 17 May 2019 21:07:57 -0400 Received: from bin-mail-out-06.binero.net ([195.74.38.229]:16505 "EHLO bin-mail-out-06.binero.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726200AbfERBH5 (ORCPT ); Fri, 17 May 2019 21:07:57 -0400 X-Halon-ID: 5cb8cb74-7909-11e9-8d05-005056917f90 Authorized-sender: niklas@soderlund.pp.se Received: from bismarck.berto.se (unknown [89.233.230.99]) by bin-vsp-out-02.atm.binero.net (Halon) with ESMTPA id 5cb8cb74-7909-11e9-8d05-005056917f90; Sat, 18 May 2019 03:07:53 +0200 (CEST) From: =?UTF-8?q?Niklas=20S=C3=B6derlund?= To: Helen Koike , linux-media@vger.kernel.org Cc: libcamera-devel@lists.libcamera.org, =?UTF-8?q?Niklas=20S=C3=B6derlund?= , =?UTF-8?q?Niklas=20S=C3=B6derlund?= Subject: [PATCH 2/3] vimc: Serialize vimc_streamer_s_stream() Date: Sat, 18 May 2019 03:07:43 +0200 Message-Id: <20190518010744.15195-3-niklas.soderlund+renesas@ragnatech.se> X-Mailer: git-send-email 2.21.0 In-Reply-To: <20190518010744.15195-1-niklas.soderlund+renesas@ragnatech.se> References: <20190518010744.15195-1-niklas.soderlund+renesas@ragnatech.se> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Prepare for multiple video streams from the same sensor by serializing vimc_streamer_s_stream(). Multiple streams will allow for multiple concurrent calls to this function that could involve the same subdevices. If that happens the internal state of the involved subdevices could go out of sync as they are being started and stopped at the same time, prevent this by serializing starting and stopping of the vimc streamer. Signed-off-by: Niklas Söderlund --- drivers/media/platform/vimc/vimc-streamer.c | 23 ++++++++++++++------- 1 file changed, 16 insertions(+), 7 deletions(-) diff --git a/drivers/media/platform/vimc/vimc-streamer.c b/drivers/media/platform/vimc/vimc-streamer.c index 26b6742594890b16..514690dca3b1187b 100644 --- a/drivers/media/platform/vimc/vimc-streamer.c +++ b/drivers/media/platform/vimc/vimc-streamer.c @@ -153,39 +153,48 @@ int vimc_streamer_s_stream(struct vimc_stream *stream, struct vimc_ent_device *ved, int enable) { + static DEFINE_MUTEX(vimc_streamer_lock); int ret; if (!stream || !ved) return -EINVAL; + ret = mutex_lock_interruptible(&vimc_streamer_lock); + if (ret) + return ret; + if (enable) { if (stream->kthread) - return 0; + goto out; ret = vimc_streamer_pipeline_init(stream, ved); if (ret) - return ret; + goto out; stream->kthread = kthread_run(vimc_streamer_thread, stream, "vimc-streamer thread"); - if (IS_ERR(stream->kthread)) - return PTR_ERR(stream->kthread); + if (IS_ERR(stream->kthread)) { + ret = PTR_ERR(stream->kthread); + goto out; + } } else { if (!stream->kthread) - return 0; + goto out; ret = kthread_stop(stream->kthread); if (ret) - return ret; + goto out; stream->kthread = NULL; vimc_streamer_pipeline_terminate(stream); } +out: + mutex_unlock(&vimc_streamer_lock); - return 0; + return ret; } EXPORT_SYMBOL_GPL(vimc_streamer_s_stream); -- 2.21.0