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 7B5DAC43334 for ; Wed, 8 Jun 2022 11:46:15 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238413AbiFHLqO (ORCPT ); Wed, 8 Jun 2022 07:46:14 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38034 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S238393AbiFHLqL (ORCPT ); Wed, 8 Jun 2022 07:46:11 -0400 Received: from hi1smtp01.de.adit-jv.com (smtp1.de.adit-jv.com [93.241.18.167]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 71707A5AB1; Wed, 8 Jun 2022 04:46:10 -0700 (PDT) Received: from hi2exch02.adit-jv.com (hi2exch02.adit-jv.com [10.72.92.28]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by hi1smtp01.de.adit-jv.com (Postfix) with ESMTPS id 64530520620; Wed, 8 Jun 2022 13:46:08 +0200 (CEST) Received: from lxhi-065 (10.72.94.21) by hi2exch02.adit-jv.com (10.72.92.28) with Microsoft SMTP Server (version=TLS1_2, cipher=TLS_ECDHE_RSA_WITH_AES_256_GCM_SHA384) id 15.1.2308.27; Wed, 8 Jun 2022 13:46:07 +0200 Date: Wed, 8 Jun 2022 13:45:35 +0200 From: Eugeniu Rosca To: Laurent Pinchart , Kieran Bingham , , CC: Michael Rodin , Koji Matsuoka , Eugen Friedrich , Eugeniu Rosca , Eugeniu Rosca Subject: Re: [RFC PATCH v2] media: renesas: vsp1: Add VSPD underrun detection & tracing Message-ID: <20220608114535.GA29244@lxhi-065> References: <1651584010-10156-1-git-send-email-erosca@de.adit-jv.com> MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Disposition: inline In-Reply-To: <1651584010-10156-1-git-send-email-erosca@de.adit-jv.com> User-Agent: Mutt/1.5.24 (2015-08-30) X-Originating-IP: [10.72.94.21] X-ClientProxiedBy: hi2exch02.adit-jv.com (10.72.92.28) To hi2exch02.adit-jv.com (10.72.92.28) Precedence: bulk List-ID: X-Mailing-List: linux-media@vger.kernel.org Dear Laurent, Dear Kieran, Dear community, On Di, Mai 03, 2022 at 03:20:10 +0200, Eugeniu Rosca wrote: > A barely noticeable (especially if hardly reproducible) display flicker > may not be the biggest concern in the development environment. However, > an automotive OEM will not only notice it, but will also be haunted by > its phenomenon/nature till it is understood in the greatest detail and > ultimately eradicated, to avoid impairing user experience. > > Troubleshooting the above without the right tools becomes a nightmare. > > Since VSPD underruns may indeed cause [1] display flicker, we believe > that having a minimal/lightweight support for detecting and logging > such events would be extremely beneficial. Obviously, this only applies > to VSP2 modules having an interface to DU (i.e. not mem2mem). > > This implementation is heavily inspired by Koji Matsuoka's work [2-3], > but has been refactored to hopefully become production/mainline-friendly > (the original feature is intended for the development environment only). > > [1] https://lore.kernel.org/linux-renesas-soc/20220421161259.GA2660@lxhi-065 > [2] https://github.com/renesas-rcar/linux-bsp/commit/3469001c3098 > ("v4l: vsp1: Add underrun hung-up workaround") > [3] https://github.com/renesas-rcar/linux-bsp/commit/12ea79975a10 > ("v4l: vsp1: Add underrun debug messege option") > > Cc: Laurent Pinchart > Cc: Kieran Bingham > Cc: Koji Matsuoka > Signed-off-by: Eugeniu Rosca > --- I apologize for another friendly reminder, but is there any chance to get a bit of attention from your side regarding this patch, which is intended to make our life easier in production? I hope the RFC tag does not convey the lack of confidence, importance and/or time spent for implementation and testing on our side. This v2 version fixed all review comments and issues which popped up during internal testing, so I am very hopeful and looking forward to your precious feedback. We have also made aware Renesas Japan that this patch is important to us, hoping that potentially there is another communication bridge between them and Renesas OSS community. Best regards, Eugeniu Rosca