From mboxrd@z Thu Jan 1 00:00:00 1970 Return-path: Received: from nblzone-211-213.nblnetworks.fi ([83.145.211.213]:46886 "EHLO hillosipuli.retiisi.org.uk" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S932771AbcIUUyv (ORCPT ); Wed, 21 Sep 2016 16:54:51 -0400 Subject: Re: [PATCH v5 2/2] media: Add a driver for the ov5645 camera sensor. To: Todor Tomov Cc: robh+dt@kernel.org, pawel.moll@arm.com, mark.rutland@arm.com, ijc+devicetree@hellion.org.uk, galak@codeaurora.org, devicetree@vger.kernel.org, mchehab@osg.samsung.com, hverkuil@xs4all.nl, geert@linux-m68k.org, matrandg@cisco.com, linux-media@vger.kernel.org, laurent.pinchart@ideasonboard.com References: <1467989679-29774-1-git-send-email-todor.tomov@linaro.org> <1467989679-29774-3-git-send-email-todor.tomov@linaro.org> <20160824101708.GI12130@valkosipuli.retiisi.org.uk> <57BDBC2F.7020902@linaro.org> <20160825071800.GK12130@valkosipuli.retiisi.org.uk> <57E292AB.9060808@linaro.org> From: Sakari Ailus Message-ID: <57E2F393.6000706@iki.fi> Date: Wed, 21 Sep 2016 23:54:43 +0300 MIME-Version: 1.0 In-Reply-To: <57E292AB.9060808@linaro.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Sender: linux-media-owner@vger.kernel.org List-ID: Hi Todor, Todor Tomov wrote: > Hi Sakari, > > One more question below: > > On 08/25/2016 10:18 AM, Sakari Ailus wrote: >>>>> + >>>>> +static struct v4l2_subdev_core_ops ov5645_core_ops = { >>>>> + .s_power = ov5645_s_power, >>>>> +}; >>>>> + >>>>> +static struct v4l2_subdev_video_ops ov5645_video_ops = { >>>>> + .s_stream = ov5645_s_stream, >>>>> +}; >>>>> + >>>>> +static struct v4l2_subdev_pad_ops ov5645_subdev_pad_ops = { >>>>> + .enum_mbus_code = ov5645_enum_mbus_code, >>>>> + .enum_frame_size = ov5645_enum_frame_size, >>>>> + .get_fmt = ov5645_get_format, >>>>> + .set_fmt = ov5645_set_format, >>>>> + .get_selection = ov5645_get_selection, >>>> >>>> Could you add init_cfg() pad op to initialise the try format and selections? >>> >>> Yes, I'll do that. > > If I follow the code correctly this init_cfg() is called whenever the device is opened, right? > This means that the format will be reset to default values every time the userspace opens the device. > So I wonder if this is what we really want, or do we want to keep the last set format instead. For > example if we use media-ctl only to get the current format, this is already enough - it opens the > subdev node and resets the format to default. What's getting set in init_cfg() called through open system call is the try format, not the active format. Whether to choose the default or current format for the try format for a file handle was discussed some years ago and we indeed settled to use the default one, since that's independent of whatever configuration happened to be set --- quite possibly by a different application. AFAIR. -- Kind regards, Sakari Ailus sakari.ailus@iki.fi