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=-15.8 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,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 0C1ACC433DB for ; Mon, 22 Feb 2021 02:04:28 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id B57D964EC3 for ; Mon, 22 Feb 2021 02:04:27 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230307AbhBVCES (ORCPT ); Sun, 21 Feb 2021 21:04:18 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:40880 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229973AbhBVCEK (ORCPT ); Sun, 21 Feb 2021 21:04:10 -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 61519C061574; Sun, 21 Feb 2021 18:03:30 -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 89DAD517; Mon, 22 Feb 2021 03:03:28 +0100 (CET) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=ideasonboard.com; s=mail; t=1613959408; bh=3+Z06nktataXtXvY4PntHi6rSu7jvSLOb2DO0aEka6s=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=r5aRkcqyQ1KbTe/kGBkz9EVuzIgryJa1II5Y3HmtN+SjOWxgsZsl4HslhOSVdP/DA 9SHy5CqJZYelCSekrf1bpXxz74LR4S+HjCHbJpyXrGJvStEBfLeJMhzqZDepmOFyC1 /PAEMQoqo9U5OdVFObptHti36qwf0TXs/sDk9aZ8= Date: Mon, 22 Feb 2021 04:03:02 +0200 From: Laurent Pinchart To: Jacopo Mondi Cc: kieran.bingham+renesas@ideasonboard.com, niklas.soderlund+renesas@ragnatech.se, geert@linux-m68k.org, Mauro Carvalho Chehab , linux-media@vger.kernel.org, linux-renesas-soc@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH 14/16] media: i2c: max9286: Initialize remotes when bound Message-ID: References: <20210216174146.106639-1-jacopo+renesas@jmondi.org> <20210216174146.106639-15-jacopo+renesas@jmondi.org> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: <20210216174146.106639-15-jacopo+renesas@jmondi.org> Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi Jacopo, Thank you for the patch. On Tue, Feb 16, 2021 at 06:41:44PM +0100, 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. > > 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); > return 0; > + } Instead of going back and forth, would it make sense to incerase the channel amplitude here, and call the init() subdev operation in a loop over all cameras ? Otherwise the patch looks good to me, but I agree with Kieran that it should probably be squashed with 13/16. > > /* > * 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); > > /* -- Regards, Laurent Pinchart