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 58268C433EF for ; Tue, 24 May 2022 07:17:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233873AbiEXHQ6 (ORCPT ); Tue, 24 May 2022 03:16:58 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:49812 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233042AbiEXHQ5 (ORCPT ); Tue, 24 May 2022 03:16:57 -0400 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 E120B5B3ED for ; Tue, 24 May 2022 00:16:55 -0700 (PDT) Received: from pendragon.ideasonboard.com (cpc89244-aztw30-2-0-cust3082.18-1.cable.virginm.net [86.31.172.11]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id 72B944A8; Tue, 24 May 2022 09:16:53 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1653376613; bh=JVVRPsiGczsgeNC9L9YBdyMJH6rW+eUC7vKSABOVKWY=; h=In-Reply-To:References:Subject:From:To:Date:From; b=NqVciWG9FDtfLV6I8pwFIuIJmPSMox8UdJ6TjMwqvP+UK1e/y53/5U2f7d3z3LZ7D Qs9J1wVMrCQ1ONMtuJNSH3wl0qGJgbEBLtEEFqs26JsoBIfxqddHisWq+gt6uKBFUy 611cc0fx9sTgTQODKwyuPjJeP1+yr8vkaNl+9epo= Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: quoted-printable In-Reply-To: <325cc388-6f65-0727-92ab-d9b87e7ade1c@xs4all.nl> References: <325cc388-6f65-0727-92ab-d9b87e7ade1c@xs4all.nl> Subject: Re: [ANN] Media Summit at ELCE Dublin: Request for Topics From: Kieran Bingham To: Hans Verkuil , linux-media@vger.kernel.org Date: Tue, 24 May 2022 08:16:51 +0100 Message-ID: <165337661126.402452.10107682065782670158@Monstersaurus> User-Agent: alot/0.10 Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Hi Hans, Quoting Hans Verkuil (2022-05-06 14:20:09) > Hi all, >=20 > Since countries are opening up again and travel is (at least for now!) a = lot easier, > I am considering a media summit during the ELCE in Dublin (Sep 13-16). >=20 > See here for more details about the conference: >=20 > https://events.linuxfoundation.org/open-source-summit-europe/ >=20 > Of course, this only makes sense if there is something to talk about. So = please reply > with any suggestions for topics! >=20 > Also please let me know if you would expect to be at such a media summit = in person. > If only a few people would be there, then there isn't much point to this. >=20 >=20 > I have two topics: >=20 > 1) Discussion of the media subsystem development process: any bottlenecks= , any ideas > for improvements? >=20 > 2) I can give a presentation on the work I've done in the CTA-861 standar= d (used by > HDMI) and the edid-decode utility. >=20 > I'd like to make a decision on whether or not it is worthwhile to do this= in a week > or two. If we wait too long it might be difficult to get a room for the s= ummit. I would like to bring up the 'fault tolerance' topic again if I can. I raised this in the past when we first started hitting the issue on Renesas platforms with multiple cameras in a single media graph, but now I think it's become more critical with desktop / laptop devices that are hitting the issue (i.e. the IPU3). Summary of issue: - Multiple cameras that can function independently successfully, are prevented from functioning or fully probing by V4L2 if one component of another camera fails to load or probe. =20 If Camera A has a VCM, and Camera B does not, Camera B will not be available at all if Camera A's VCM is not fully probed, even though Camera B can be fully functional and complete. Even if Camera A does not have the VCM probed, it may still function successfully (with a fixed focal position) - but our current implementation will mean that it will not even be available to capture images. We talked about this quite a long time ago, and I believe the general consensus was that we can have events on the media graph. But unfortunately at the time, there was no development scheduled on that, and it wasn't something I was able to continue at the time. I'd like to bring it up to refresh the topic, and see if we can make some progress as it's now affecting more general devices. -- Kieran >=20 > Regards, >=20 > Hans