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=-8.2 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,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 4A073C2BA19 for ; Wed, 15 Apr 2020 10:07:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 2D8B520768 for ; Wed, 15 Apr 2020 10:07:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S2896179AbgDOKHv (ORCPT ); Wed, 15 Apr 2020 06:07:51 -0400 Received: from hostingweb31-40.netsons.net ([89.40.174.40]:33840 "EHLO hostingweb31-40.netsons.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S2896154AbgDOKHc (ORCPT ); Wed, 15 Apr 2020 06:07:32 -0400 Received: from [88.147.20.223] (port=52218 helo=[192.168.77.62]) by hostingweb31.netsons.net with esmtpsa (TLS1.2) tls TLS_ECDHE_RSA_WITH_AES_128_GCM_SHA256 (Exim 4.93) (envelope-from ) id 1jOex2-009Eu1-UU; Wed, 15 Apr 2020 12:07:24 +0200 Subject: Re: [RFC PATCH v2 6/6] i2c: core: hand over reserved devices when requesting ancillary addresses To: Wolfram Sang , linux-i2c@vger.kernel.org Cc: linux-renesas-soc@vger.kernel.org, linux-i3c@lists.infradead.org, Kieran Bingham , =?UTF-8?Q?Niklas_S=c3=b6derlund?= , Jacopo Mondi , Laurent Pinchart , Vladimir Zapolskiy , linux-kernel@vger.kernel.org References: <20200318150059.21714-1-wsa+renesas@sang-engineering.com> <20200318150059.21714-7-wsa+renesas@sang-engineering.com> From: Luca Ceresoli Message-ID: <610bbd01-e245-3320-c315-7a5c945a700d@lucaceresoli.net> Date: Wed, 15 Apr 2020 12:07:24 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.4.1 MIME-Version: 1.0 In-Reply-To: <20200318150059.21714-7-wsa+renesas@sang-engineering.com> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - hostingweb31.netsons.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - lucaceresoli.net X-Get-Message-Sender-Via: hostingweb31.netsons.net: authenticated_id: luca@lucaceresoli.net X-Authenticated-Sender: hostingweb31.netsons.net: luca@lucaceresoli.net X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, On 18/03/20 16:00, Wolfram Sang wrote: > With i2c_new_ancillary_address, we can check if the intended driver is > requesting a reserved address. Update the function to do these checks. > If the check passes, the "reserved" device will become a regular "dummy" > device. > > Signed-off-by: Wolfram Sang > --- > drivers/i2c/i2c-core-base.c | 24 ++++++++++++++++++++++-- > 1 file changed, 22 insertions(+), 2 deletions(-) > > diff --git a/drivers/i2c/i2c-core-base.c b/drivers/i2c/i2c-core-base.c > index 84464e439df5..81fb320de28d 100644 > --- a/drivers/i2c/i2c-core-base.c > +++ b/drivers/i2c/i2c-core-base.c > @@ -974,7 +974,9 @@ struct i2c_client *i2c_new_ancillary_device(struct i2c_client *client, > const char *name, > u16 default_addr) > { > - struct device_node *np = client->dev.of_node; > + struct device_node *reserved_np, *np = client->dev.of_node; > + struct device *reserved_dev, *adapter_dev = &client->adapter->dev; > + struct i2c_client *reserved_client = NULL; > u32 addr = default_addr; > int i; > > @@ -984,7 +986,25 @@ struct i2c_client *i2c_new_ancillary_device(struct i2c_client *client, > of_property_read_u32_index(np, "reg", i, &addr); > } > > - dev_dbg(&client->adapter->dev, "Address for %s : 0x%x\n", name, addr); > + dev_info(adapter_dev, "Address for %s : 0x%x\n", name, addr); Here if we have two identical chips on the same bus, they probably will both add an ancillary device with the same name. Then a message like: i2c i2c-0: ds90ub954-q1: Address for rxport0: 0x40 won't tell which ds90ub954-q1 device is using that address. I'd rather disambiguate using something like: dev_info(adapter_dev, "%s: Address for %s: 0x%x\n", dev_name(&client->dev), name, addr); Sure, this issue did exist before this patch, but since the line is being promoted from dbg to info (which is OK), it's probably a good idea to improve the content, perhaps in a separate patch. Except for that, I tested the patch and it's working fine. -- Luca