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=-8.7 required=3.0 tests=BAYES_00, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_CR_TRAILER,MAILING_LIST_MULTI, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED autolearn=unavailable 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 197E9C433E0 for ; Wed, 17 Feb 2021 08:18:46 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C2F5864E2E for ; Wed, 17 Feb 2021 08:18:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231837AbhBQISX (ORCPT ); Wed, 17 Feb 2021 03:18:23 -0500 Received: from mail-ot1-f54.google.com ([209.85.210.54]:39986 "EHLO mail-ot1-f54.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231697AbhBQIST (ORCPT ); Wed, 17 Feb 2021 03:18:19 -0500 Received: by mail-ot1-f54.google.com with SMTP id b8so6701889oti.7; Wed, 17 Feb 2021 00:18:03 -0800 (PST) X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:mime-version:references:in-reply-to:from:date :message-id:subject:to:cc; bh=slle50kgoNxJbklUkZhTyyJhtMMKbICkNQUByIjAzOU=; b=iK5NUiRbfWp5C3AnluH4PAKVYepg0gkT3GiKy3fDasZqIB06bL4mO57S8MivqPwuYg XQh91xSZSBeK6O1ZSA/LLXhHFA7uc/rhAjUKVaZTMjbOtWA9dKiPwSR/kdV6UcytA3zg 5mGSznWb7AD2axI6WuW+jqxjO7r9ueVtqhHNBHDiinIpJ1GMIxjR8rQmpL7KSSWjUqPF m62R2ZL9VHgfEQU/mGQtPI8sBiJkJaT23sv9a18YbHtOVOG+/3gCKoJpaSjfqlRzVs6Y MixdIHT+QUa83eVoVkjfunOjTuty/YpN1ldscTjt77tbJ45OnW4dioKHey6RN15Xm11n VO+Q== X-Gm-Message-State: AOAM533Q9rLpbS5BDv3j60pod9MCcoJp8DLZySUieB14kFn/5OYTIyr1 pMP4x0KY9Ip9ckU/bYn88RYlBQRRAqbv/VT81Nw= X-Google-Smtp-Source: ABdhPJy0Zsxob69r2ILVf8ZjCZjUznUmjxaT0KTXuVAzvgy2kE6lxQwrLRsNkKaeb9HIZoMOLqx8vtmR13O1ymChKwU= X-Received: by 2002:a05:6830:148d:: with SMTP id s13mr17020227otq.250.1613549858180; Wed, 17 Feb 2021 00:17:38 -0800 (PST) MIME-Version: 1.0 References: <20210216174146.106639-1-jacopo+renesas@jmondi.org> <20210216174146.106639-14-jacopo+renesas@jmondi.org> In-Reply-To: <20210216174146.106639-14-jacopo+renesas@jmondi.org> From: Geert Uytterhoeven Date: Wed, 17 Feb 2021 09:17:27 +0100 Message-ID: Subject: Re: [PATCH 13/16] media: i2c: rdacm2x: Implement .init() subdev op To: Jacopo Mondi Cc: Kieran Bingham , Laurent Pinchart , =?UTF-8?Q?Niklas_S=C3=B6derlund?= , Mauro Carvalho Chehab , Linux Media Mailing List , Linux-Renesas , Linux Kernel Mailing List Content-Type: text/plain; charset="UTF-8" Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Feb 16, 2021 at 6:41 PM Jacopo Mondi wrote: > The current probe() procedure of the RDACM20 and RDACM20 performs > initialization of the serializer image sensors and increases the noise > immunity threshold as last operation, which is then compensated by the > remote deserializer by increasing the reverse channel signal amplitude > once all remotes have bound. > > The probe routine is then run without noise immunity activated which > in noisy environment conditions makes the probe sequence less reliable as > the chips configuration requires a relevant amount of i2c transactions. > > Break chip initialization in two: > - At probe time only configure the serializer's reverse channel with > noise immunity activated, to reduce the number of transactions deactivated? > performed without noise immunity protection > - Move the chips initialization to the .init() core subdev operation to > be invoked by the deserializer after the camera has probed and it has > increased the reverse channel amplitude > > Signed-off-by: Jacopo Mondi Gr{oetje,eeting}s, Geert -- Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert@linux-m68k.org In personal conversations with technical people, I call myself a hacker. But when I'm talking to journalists I just say "programmer" or something like that. -- Linus Torvalds