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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id B5011C433F5 for ; Tue, 14 Dec 2021 22:22:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233326AbhLNWWN (ORCPT ); Tue, 14 Dec 2021 17:22:13 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:57744 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231132AbhLNWWM (ORCPT ); Tue, 14 Dec 2021 17:22:12 -0500 Received: from perceval.ideasonboard.com (perceval.ideasonboard.com [IPv6:2001:4b98:dc2:55:216:3eff:fef7:d647]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 83237C061574 for ; Tue, 14 Dec 2021 14:22:12 -0800 (PST) Received: from pendragon.ideasonboard.com (62-78-145-57.bb.dnainternet.fi [62.78.145.57]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id B30B48C4; Tue, 14 Dec 2021 23:22:10 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1639520530; bh=Djanrb1qArmdt1u2pGupDqDFG1HBvjOlso+yEQW/YtA=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=NplJSJh8y0uUkg1U/xTMlIyorkI6pfgNT8GxSFyg86uOFCdSLBSeZ7cgxGsZotiUH 634wHyI8zDmMCy7nTjJMsPnz0PuNQT9puw0cqJVNQhBP6GB/XkV+d2zP2M/VMW1xgp IRxHf4EuxtEd2tZrhMh6P+EEY5d0C0gHxPJ8Josw= Date: Wed, 15 Dec 2021 00:22:08 +0200 From: Laurent Pinchart To: Daniel Scally Cc: linux-media@vger.kernel.org, libcamera-devel@lists.libcamera.org, sakari.ailus@linux.intel.com, hanlinchen@chromium.org, tfiga@chromium.org, hdegoede@redhat.com, kieran.bingham@ideasonboard.com, hpa@redhat.com Subject: Re: [PATCH 5/5] media: v4l2-async: Create links during v4l2_async_match_notify() Message-ID: References: <20211213232849.40071-1-djrscally@gmail.com> <20211213232849.40071-6-djrscally@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20211213232849.40071-6-djrscally@gmail.com> Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Hi Daniel, Thank you for the patch. On Mon, Dec 13, 2021 at 11:28:49PM +0000, Daniel Scally wrote: > Upon an async fwnode match, there's some typical behaviour that the > notifier and matching subdev will want to do. For example, a notifier > representing a sensor matching to an async subdev representing its > VCM will want to create an ancillary link to expose that relationship > to userspace. > > To avoid lots of code in individual drivers, try to build these links > within v4l2 core. > > Signed-off-by: Daniel Scally > --- > Changes since the rfc: > > - None > > drivers/media/v4l2-core/v4l2-async.c | 51 ++++++++++++++++++++++++++++ > 1 file changed, 51 insertions(+) > > diff --git a/drivers/media/v4l2-core/v4l2-async.c b/drivers/media/v4l2-core/v4l2-async.c > index 0404267f1ae4..6575b1cbe95f 100644 > --- a/drivers/media/v4l2-core/v4l2-async.c > +++ b/drivers/media/v4l2-core/v4l2-async.c > @@ -275,6 +275,45 @@ v4l2_async_nf_try_complete(struct v4l2_async_notifier *notifier) > static int > v4l2_async_nf_try_all_subdevs(struct v4l2_async_notifier *notifier); > > +static int > +__v4l2_async_create_ancillary_link(struct v4l2_async_notifier *notifier, > + struct v4l2_subdev *sd) > +{ > + struct media_link *link; > + > + if (sd->entity.function != MEDIA_ENT_F_LENS && > + sd->entity.function != MEDIA_ENT_F_FLASH) > + return -EINVAL; > + > + link = media_create_ancillary_link(¬ifier->sd->entity, &sd->entity, Is there a guarantee at this point that notifier->sd->entity has already been registered with the media_device ? That's done by media_device_register_entity() called from v4l2_device_register_subdev(). > + MEDIA_LNK_FL_ENABLED | > + MEDIA_LNK_FL_IMMUTABLE); > + > + return IS_ERR(link) ? PTR_ERR(link) : 0; > +} > + > +/* > + * Setup links on behalf of the notifier and subdev, where it's obvious what s/Setup/Create/ ("link setup" refers to another operation, enabling and disabling links at runtime) > + * should be done. At the moment, we only support cases where the notifier > + * is a sensor and the subdev is a lens. s/sensor/camera sensor/ s/lens/lens controller/ > + * > + * TODO: Setup pad links if the notifier's function is MEDIA_ENT_F_VID_IF_BRIDGE > + * and the subdev's is MEDIA_ENT_F_CAM_SENSOR > + */ > +static int v4l2_async_try_create_links(struct v4l2_async_notifier *notifier, > + struct v4l2_subdev *sd) > +{ > + if (!notifier->sd) > + return 0; > + > + switch (notifier->sd->entity.function) { > + case MEDIA_ENT_F_CAM_SENSOR: > + return __v4l2_async_create_ancillary_link(notifier, sd); > + default: > + return 0; > + } > +} > + > static int v4l2_async_match_notify(struct v4l2_async_notifier *notifier, > struct v4l2_device *v4l2_dev, > struct v4l2_subdev *sd, > @@ -293,6 +332,18 @@ static int v4l2_async_match_notify(struct v4l2_async_notifier *notifier, > return ret; > } > > + /* > + * Depending of the function of the entities involved, we may want to > + * create links between them (for example between a sensor and its lens > + * or between a sensor's source pad and the connected device's sink > + * pad) s/)/)./ > + */ > + ret = v4l2_async_try_create_links(notifier, sd); > + if (ret) { > + v4l2_device_unregister_subdev(sd); > + return ret; > + } > + > /* Remove from the waiting list */ > list_del(&asd->list); > sd->asd = asd; -- Regards, Laurent Pinchart