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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS, UNPARSEABLE_RELAY,USER_AGENT_SANE_1 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 E77EFC433DF for ; Tue, 30 Jun 2020 10:56:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id CBF56207F9 for ; Tue, 30 Jun 2020 10:56:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1732632AbgF3K4u (ORCPT ); Tue, 30 Jun 2020 06:56:50 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49040 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1732592AbgF3K4u (ORCPT ); Tue, 30 Jun 2020 06:56:50 -0400 Received: from bhuna.collabora.co.uk (bhuna.collabora.co.uk [IPv6:2a00:1098:0:82:1000:25:2eeb:e3e3]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id D1A89C061755 for ; Tue, 30 Jun 2020 03:56:49 -0700 (PDT) Received: from [127.0.0.1] (localhost [127.0.0.1]) (Authenticated sender: dafna) with ESMTPSA id 864782A0538 Subject: Re: [PATCH 20/25] media: ov5647: Program mode only if it has changed To: Jacopo Mondi Cc: mchehab@kernel.org, sakari.ailus@linux.intel.com, hverkuil@xs4all.nl, laurent.pinchart@ideasonboard.com, roman.kovalivskyi@globallogic.com, dave.stevenson@raspberrypi.org, naush@raspberrypi.com, mrodin@de.adit-jv.com, hugues.fruchet@st.com, mripard@kernel.org, aford173@gmail.com, sudipi@jp.adit-jv.com, andrew_gabbasov@mentor.com, erosca@de.adit-jv.com, linux-media@vger.kernel.org, libcamera-devel@lists.libcamera.org, dafna Hirschfeld References: <20200623100815.10674-1-jacopo@jmondi.org> <20200623165550.45835-1-jacopo@jmondi.org> <80139e40-914f-c547-922f-91fe3f611202@collabora.com> <20200630074305.soctqoaqirfdnvv2@uno.localdomain> <20200630100651.ikjcazgbvoq2hab4@uno.localdomain> From: Dafna Hirschfeld Message-ID: Date: Tue, 30 Jun 2020 12:56:44 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.8.0 MIME-Version: 1.0 In-Reply-To: <20200630100651.ikjcazgbvoq2hab4@uno.localdomain> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org On 30.06.20 12:06, Jacopo Mondi wrote: > Hi Dafna, > > On Tue, Jun 30, 2020 at 11:32:12AM +0200, Dafna Hirschfeld wrote: >> >> >> On 30.06.20 09:43, Jacopo Mondi wrote: >>> Hi Dafna, >>> >>> On Mon, Jun 29, 2020 at 07:48:16PM +0200, Dafna Hirschfeld wrote: >>>> >>>> >>>> On 23.06.20 18:55, Jacopo Mondi wrote: >>>>> Store in the driver structure a pointer to the currently applied mode >>>>> and program a new one at s_stream(1) time only if it has changed. >>>> >>>> Hi, >>>> I think this can be more readably implemented with a 'is_streaming' boolean >>>> field. >>> >>> How would you like to use an 'is_streaming' flag to decide if the >>> sensor mode has to be updated ? >> >> since 'current_mode' is set to NULL upon `ov5647_stream_off` >> and you return from 'ov5647_set_stream' immediately if 'mode == current_mode' >> it seem very similar to returning immediately from 'ov5647_set_stream' if the >> device is currently streaming. > > No, the code returns immediately from ov5647_set_mode() if mode == > current_mode. The modes comparison makes sure the sensor is not > reprogrammed if the mode hasn't changed. The remaning part of > s_stream() is executed regardless of the mode configuration. Am I > missing some part of the picture ? > >> >> But actually in this patch it seems to be possible to change the mode >> while streaming, if the callbacks are executed: >> >> s_stream(1) >> s_fmt >> s_stream(1) >> >> which is maybe a bug? > > The new format is stored in sensor->mode, and applied at the next > s_stream(1) operation if it differs from the already programmed one, > at least, this is how it is intended to work, have you found any > failing s_stream/set_fmt/s_stream which could be caused by a bug ? What I meant is that there could be valid sequence of calls s_stream(enable=1) s_fmt s_stream(enable=1) For example if two video devices are connected to the sensor and they stream simultaneously. There was a discussion about adding a code to the core to follow the s_stream callback and call it only if the subdev is not streaming but currently subdevs should support it themselves. Thanks, Dafna > > Thanks > j >> >> Thanks, >> Dafna >> >>> >>> Thanks >>> j >>> >>> >>>> >>>> Thanks, >>>> Dafna >>>> >>>>> >>>>> Signed-off-by: Jacopo Mondi >>>>> --- >>>>> drivers/media/i2c/ov5647.c | 16 +++++++++++++++- >>>>> 1 file changed, 15 insertions(+), 1 deletion(-) >>>>> >>>>> diff --git a/drivers/media/i2c/ov5647.c b/drivers/media/i2c/ov5647.c >>>>> index 39e320f321bd8..ac114269e1c73 100644 >>>>> --- a/drivers/media/i2c/ov5647.c >>>>> +++ b/drivers/media/i2c/ov5647.c >>>>> @@ -96,6 +96,7 @@ struct ov5647 { >>>>> bool clock_ncont; >>>>> struct v4l2_ctrl_handler ctrls; >>>>> struct ov5647_mode *mode; >>>>> + struct ov5647_mode *current_mode; >>>>> }; >>>>> static inline struct ov5647 *to_sensor(struct v4l2_subdev *sd) >>>>> @@ -750,9 +751,13 @@ static int ov5647_set_virtual_channel(struct v4l2_subdev *sd, int channel) >>>>> static int ov5647_set_mode(struct v4l2_subdev *sd) >>>>> { >>>>> struct i2c_client *client = v4l2_get_subdevdata(sd); >>>>> + struct ov5647 *sensor = to_sensor(sd); >>>>> u8 resetval, rdval; >>>>> int ret; >>>>> + if (sensor->mode == sensor->current_mode) >>>>> + return 0; >>>>> + >>>>> ret = ov5647_read(sd, OV5647_SW_STANDBY, &rdval); >>>>> if (ret < 0) >>>>> return ret; >>>>> @@ -778,6 +783,8 @@ static int ov5647_set_mode(struct v4l2_subdev *sd) >>>>> return ret; >>>>> } >>>>> + sensor->current_mode = sensor->mode; >>>>> + >>>>> return 0; >>>>> } >>>>> @@ -816,6 +823,7 @@ static int ov5647_stream_on(struct v4l2_subdev *sd) >>>>> static int ov5647_stream_off(struct v4l2_subdev *sd) >>>>> { >>>>> + struct ov5647 *sensor = to_sensor(sd); >>>>> int ret; >>>>> ret = ov5647_write(sd, OV5647_REG_MIPI_CTRL00, MIPI_CTRL00_CLOCK_LANE_GATE | >>>>> @@ -827,7 +835,13 @@ static int ov5647_stream_off(struct v4l2_subdev *sd) >>>>> if (ret < 0) >>>>> return ret; >>>>> - return ov5647_write(sd, OV5640_REG_PAD_OUT, 0x01); >>>>> + ret = ov5647_write(sd, OV5640_REG_PAD_OUT, 0x01); >>>>> + if (ret < 0) >>>>> + return ret; >>>>> + >>>>> + sensor->current_mode = NULL; >>>>> + >>>>> + return 0; >>>>> } >>>>> static int set_sw_standby(struct v4l2_subdev *sd, bool standby) >>>>>