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=-17.3 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, URIBL_BLOCKED,USER_AGENT_SANE_1 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 742AFC43381 for ; Thu, 18 Feb 2021 18:28:45 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2C93464E92 for ; Thu, 18 Feb 2021 18:28:45 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S232140AbhBRS2b (ORCPT ); Thu, 18 Feb 2021 13:28:31 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38194 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S232851AbhBRQFn (ORCPT ); Thu, 18 Feb 2021 11:05:43 -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 B3808C061756 for ; Thu, 18 Feb 2021 08:04:58 -0800 (PST) Received: from [192.168.0.20] (cpc89244-aztw30-2-0-cust3082.18-1.cable.virginm.net [86.31.172.11]) by perceval.ideasonboard.com (Postfix) with ESMTPSA id ED42F3E7; Thu, 18 Feb 2021 17:00:18 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1613664019; bh=+fg4ZdYS3PaFeKu9P08ymW/RCB8AxtGAFSyL34K0jjU=; h=Reply-To:Subject:To:Cc:References:From:Date:In-Reply-To:From; b=pOIMR0ovOb19HoGIScfXBqUfGhjiMfaWVe4lAro4kD3Ad4dt3lKR0LOy+f2xggAiK 86eRjaiidiGAwzgbZJ+W2W7kUDfxKefPRWmfnlVZXkJeUEoKkBiIEY4Pro/DG8/VnB XcC/gz8ff15aeURrsdDkDNvY1Wx+e5WjrF94EAmI= Reply-To: kieran.bingham+renesas@ideasonboard.com Subject: Re: [PATCH 14/16] media: i2c: max9286: Initialize remotes when bound To: Jacopo Mondi , laurent.pinchart+renesas@ideasonboard.com, niklas.soderlund+renesas@ragnatech.se, geert@linux-m68k.org Cc: Mauro Carvalho Chehab , linux-media@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-kernel@vger.kernel.org References: <20210216174146.106639-1-jacopo+renesas@jmondi.org> <20210216174146.106639-15-jacopo+renesas@jmondi.org> From: Kieran Bingham Organization: Ideas on Board Message-ID: <2c4299af-4e1f-9a72-b24b-bb7876bb1e5b@ideasonboard.com> Date: Thu, 18 Feb 2021 16:00:16 +0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.10.0 MIME-Version: 1.0 In-Reply-To: <20210216174146.106639-15-jacopo+renesas@jmondi.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-GB Content-Transfer-Encoding: 7bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 16/02/2021 17:41, Jacopo Mondi wrote: > With the introduction of the .init() core subdev operation in the > max9271 GMSL serializer, the max9286 deserializer needs to explicitly > initialize the remote devices by calling the .init() subdev operation on > each probed camera. > > Call the .init() subdev operation at remote bound time and toggle > the reverse channel amplitude to compensate for the remote ends > noise immunity threshold. > Should this patch be merged with the previous one to keep the RDACM2x and max9286 usage aligned? I expect it won't compile fail, but it would fail a test (if bisecting was testing the capture). Seems to look ok, given the previous patch as a dependency: Reviewed-by: Kieran Bingham > Signed-off-by: Jacopo Mondi > --- > drivers/media/i2c/max9286.c | 24 +++++++++++++++++++----- > 1 file changed, 19 insertions(+), 5 deletions(-) > > diff --git a/drivers/media/i2c/max9286.c b/drivers/media/i2c/max9286.c > index 7913b5f2249e..c41284de89b6 100644 > --- a/drivers/media/i2c/max9286.c > +++ b/drivers/media/i2c/max9286.c > @@ -554,25 +554,39 @@ static int max9286_notify_bound(struct v4l2_async_notifier *notifier, > dev_dbg(&priv->client->dev, "Bound %s pad: %u on index %u\n", > subdev->name, src_pad, index); > > + /* > + * Initialize the remote camera. Increase the channel amplitude > + * to compensate for the remote noise immunity threshold. > + */ > + max9286_reverse_channel_setup(priv, MAX9286_REV_AMP_HIGH); > + ret = v4l2_subdev_call(subdev, core, init, 0); > + if (ret) { > + dev_err(&priv->client->dev, > + "Failed to initialize camera device %u\n", index); > + return ret; > + } > + > /* > * We can only register v4l2_async_notifiers, which do not provide a > * means to register a complete callback. bound_sources allows us to > * identify when all remote serializers have completed their probe. > */ > - if (priv->bound_sources != priv->source_mask) > + if (priv->bound_sources != priv->source_mask) { > + /* > + * If not all remotes have probed yet, restore the initial > + * reverse channel amplitude to allow the next camera to probe. > + */ > + max9286_reverse_channel_setup(priv, priv->init_rev_chan_mv); Oh - wow, now I see why we definitely need to store both the initial and the current value. > return 0; > + } > > /* > * All enabled sources have probed and enabled their reverse control > * channels: > - * > - * - Increase the reverse channel amplitude to compensate for the > - * remote ends high threshold > * - Verify all configuration links are properly detected > * - Disable auto-ack as communication on the control channel are now > * stable. > */ > - max9286_reverse_channel_setup(priv, MAX9286_REV_AMP_HIGH); > max9286_check_config_link(priv, priv->source_mask); > > /* >