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=-18.7 required=3.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER, INCLUDES_PATCH,MAILING_LIST_MULTI,NICE_REPLY_A,SPF_HELO_NONE,SPF_PASS, 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 6E79AC433EF for ; Thu, 16 Sep 2021 06:17:52 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 58B49611C8 for ; Thu, 16 Sep 2021 06:17:52 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S234524AbhIPGTK (ORCPT ); Thu, 16 Sep 2021 02:19:10 -0400 Received: from perceval.ideasonboard.com ([213.167.242.64]:58226 "EHLO perceval.ideasonboard.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S234527AbhIPGTI (ORCPT ); Thu, 16 Sep 2021 02:19:08 -0400 Received: from [192.168.1.111] (91-158-153-130.elisa-laajakaista.fi [91.158.153.130]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id D7DED2A5; Thu, 16 Sep 2021 08:17:45 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1631773066; bh=iYCPuib0MItJiRSPhtg5wHxL/ZiTUmi3/zxckQ6Q/ww=; h=Subject:To:Cc:References:From:Date:In-Reply-To:From; b=kWpZmfMm+JAP5EYEHZIl9WirfGFULX1NQXQmBdf28x+b8n+oqa31+vyNwuL5//Sor RDpinWnf+NAE8Zg84T8Vz0gk43UrUG0AJbcHuQ4g5WbdmZAE1oy0YoWBBchs/6LjSA LL+NVoNhzx8oOW+zZ9oX4+jZyFXp0cKpHHtxVfko= Subject: Re: [PATCH v8 02/36] media: subdev: add active state to struct v4l2_subdev To: Jacopo Mondi Cc: linux-media@vger.kernel.org, sakari.ailus@linux.intel.com, Jacopo Mondi , Laurent Pinchart , niklas.soderlund+renesas@ragnatech.se, Mauro Carvalho Chehab , Hans Verkuil , Pratyush Yadav , Lokesh Vutla References: <20210830110116.488338-1-tomi.valkeinen@ideasonboard.com> <20210830110116.488338-3-tomi.valkeinen@ideasonboard.com> <20210915094403.cazj7bjampnes4ba@uno.localdomain> From: Tomi Valkeinen Message-ID: <8e322af6-c010-f906-f733-6d3f770a48fc@ideasonboard.com> Date: Thu, 16 Sep 2021 09:17:42 +0300 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.13.0 MIME-Version: 1.0 In-Reply-To: <20210915094403.cazj7bjampnes4ba@uno.localdomain> Content-Type: text/plain; charset=utf-8; format=flowed Content-Language: en-US Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Hi, On 15/09/2021 12:44, Jacopo Mondi wrote: > Hi Tomi, > > On Mon, Aug 30, 2021 at 02:00:42PM +0300, Tomi Valkeinen wrote: >> Add a new 'state' field to struct v4l2_subdev to which we can store the >> active state of a subdev. This will place the subdev configuration into >> a known place, allowing us to use the state directly from the v4l2 >> framework, thus simplifying the drivers. >> >> We also add v4l2_subdev_alloc_state() and v4l2_subdev_free_state(), >> which need to be used by the drivers that support subdev state in struct >> v4l2_subdev. >> >> Signed-off-by: Tomi Valkeinen >> --- >> drivers/media/v4l2-core/v4l2-subdev.c | 21 ++++++++++++++++ >> include/media/v4l2-subdev.h | 36 +++++++++++++++++++++++++++ >> 2 files changed, 57 insertions(+) >> >> diff --git a/drivers/media/v4l2-core/v4l2-subdev.c b/drivers/media/v4l2-core/v4l2-subdev.c >> index 26a34a8e3d37..e1a794f69815 100644 >> --- a/drivers/media/v4l2-core/v4l2-subdev.c >> +++ b/drivers/media/v4l2-core/v4l2-subdev.c >> @@ -943,3 +943,24 @@ void v4l2_subdev_notify_event(struct v4l2_subdev *sd, >> v4l2_subdev_notify(sd, V4L2_DEVICE_NOTIFY_EVENT, (void *)ev); >> } >> EXPORT_SYMBOL_GPL(v4l2_subdev_notify_event); >> + >> +int v4l2_subdev_alloc_state(struct v4l2_subdev *sd) >> +{ >> + struct v4l2_subdev_state *state; >> + >> + state = v4l2_alloc_subdev_state(sd); > > So, I think this is one source of confusion about init_cfg. > > v4l2_alloc_subdev_state() calls init_cfg() and 'state-aware' driver > are now supposed to allocate their state by calling > v4l2_subdev_alloc_state(), in the same way as the core does for the > file-handle ones. > > This will lead to init_cfg to be called for the 'active' (ie owned by > the subdev) state, and then you need to add context to the state (by > adding a 'which' field) to know what state you're dealing with. > > According to the init_cfg() documentation > > * @init_cfg: initialize the pad config to default values > > the op has to be called in order to initialize the per-file-handle > context, not the active one. I have missed updating the documentation there =). > I would rather just embed 'struct v4l2_subdev_state' in 'struct > v4l2_subdev', have the core going through the Why would embedding the state change anything? > 'v4l2_subdev_alloc_state()' to initialize the per-fh state, but have > drivers initialize their own state at probe time. If they need for > some reason to access their 'active' state at init_cfg() time, they > caan fish it from their subdev. > > If I'm not mistaken this will remove the need to have a which filed in > the state, as I think the 'context' should be inferred from the > 'which' argument embedded in the ops-specific structures, and not held > in the state itself. I'll comment on these in the next reply, as your second mail covered the same topics. Tomi