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=-6.0 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, MAILING_LIST_MULTI,MENTIONS_GIT_HOSTING,SPF_HELO_NONE,SPF_PASS autolearn=ham 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 E057CC433E0 for ; Mon, 22 Jun 2020 11:07:55 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C261420706 for ; Mon, 22 Jun 2020 11:07:55 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727908AbgFVLHz convert rfc822-to-8bit (ORCPT ); Mon, 22 Jun 2020 07:07:55 -0400 Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:2248 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727852AbgFVLHz (ORCPT ); Mon, 22 Jun 2020 07:07:55 -0400 Received: from pps.filterd (m0187473.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.42/8.16.0.42) with SMTP id 05MB2skj123609; Mon, 22 Jun 2020 07:07:49 -0400 Received: from pps.reinject (localhost [127.0.0.1]) by mx0a-001b2d01.pphosted.com with ESMTP id 31sk2r55wr-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 22 Jun 2020 07:07:48 -0400 Received: from m0187473.ppops.net (m0187473.ppops.net [127.0.0.1]) by pps.reinject (8.16.0.36/8.16.0.36) with SMTP id 05MB3ONT125267; Mon, 22 Jun 2020 07:07:46 -0400 Received: from ppma04ams.nl.ibm.com (63.31.33a9.ip4.static.sl-reverse.com [169.51.49.99]) by mx0a-001b2d01.pphosted.com with ESMTP id 31sk2r55vg-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 22 Jun 2020 07:07:46 -0400 Received: from pps.filterd (ppma04ams.nl.ibm.com [127.0.0.1]) by ppma04ams.nl.ibm.com (8.16.0.42/8.16.0.42) with SMTP id 05MAoPOe020523; Mon, 22 Jun 2020 11:07:42 GMT Received: from b06avi18878370.portsmouth.uk.ibm.com (b06avi18878370.portsmouth.uk.ibm.com [9.149.26.194]) by ppma04ams.nl.ibm.com with ESMTP id 31sa37u79d-1 (version=TLSv1.2 cipher=ECDHE-RSA-AES256-GCM-SHA384 bits=256 verify=NOT); Mon, 22 Jun 2020 11:07:42 +0000 Received: from d06av21.portsmouth.uk.ibm.com (d06av21.portsmouth.uk.ibm.com [9.149.105.232]) by b06avi18878370.portsmouth.uk.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id 05MB7e7w63439116 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=OK); Mon, 22 Jun 2020 11:07:40 GMT Received: from d06av21.portsmouth.uk.ibm.com (unknown [127.0.0.1]) by IMSVA (Postfix) with ESMTP id 49FCF5204F; Mon, 22 Jun 2020 11:07:40 +0000 (GMT) Received: from [9.85.120.237] (unknown [9.85.120.237]) by d06av21.portsmouth.uk.ibm.com (Postfix) with ESMTPS id C72DF52050; Mon, 22 Jun 2020 11:07:38 +0000 (GMT) Content-Type: text/plain; charset=utf-8 Mime-Version: 1.0 (Mac OS X Mail 13.4 \(3608.80.23.2.2\)) Subject: Re: Leds-gpio discarding the entries in /sys/class/leds : Linux 5.4.38 From: Vishwanatha Subbanna In-Reply-To: <0391e655-d6ef-b459-0c8c-b65d232006c4@gmail.com> Date: Mon, 22 Jun 2020 16:37:36 +0530 Cc: pavel@ucw.cz, dmurphy@ti.com, linux-leds@vger.kernel.org Content-Transfer-Encoding: 8BIT Message-Id: References: <124c90ad-e239-d5e8-4c86-be96e7aa7c26@gmail.com> <6644A4B6-E6DA-413B-97CA-1E4D199D52CE@linux.vnet.ibm.com> <4b7e95e5-0889-1502-2f0b-796874f90083@gmail.com> <1084104E-3840-4BCE-A58F-8447DFC214FD@linux.vnet.ibm.com> <0391e655-d6ef-b459-0c8c-b65d232006c4@gmail.com> To: Jacek Anaszewski X-Mailer: Apple Mail (2.3608.80.23.2.2) X-TM-AS-GCONF: 00 X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10434:6.0.216,18.0.687 definitions=2020-06-22_04:2020-06-22,2020-06-22 signatures=0 X-Proofpoint-Spam-Details: rule=outbound_notspam policy=outbound score=0 mlxlogscore=999 suspectscore=0 clxscore=1015 lowpriorityscore=0 bulkscore=0 cotscore=-2147483648 mlxscore=0 priorityscore=1501 malwarescore=0 adultscore=0 spamscore=0 phishscore=0 impostorscore=0 classifier=spam adjust=0 reason=mlx scancount=1 engine=8.12.0-2004280000 definitions=main-2006220084 Sender: linux-leds-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-leds@vger.kernel.org Hi Jacek, > On 22-Jun-2020, at 4:24 PM, Jacek Anaszewski wrote: > > Hi Vishwanatha, > > On 6/22/20 8:58 AM, Vishwanatha Subbanna wrote: >> Thank you very much Jacek. >>> On 22-Jun-2020, at 3:12 AM, Jacek Anaszewski wrote: >>> >>> Hi Vishwanatha, >>> >>> On 6/20/20 7:25 PM, Vishwanatha Subbanna wrote: >>>> Hi Jacek, >>>> Thank you very much for the quick response. Greatly appreciate that. >>> >>> You're welcome. >>> >>>>> On 20-Jun-2020, at 3:27 AM, Jacek Anaszewski wrote: >>>>> >>>>> Hi Vishwanatha, >>>>> >>>>> Please refer to Documentation/devicetree/bindings/leds/leds-pca955x.txt. >>>>> >>>>> At first glance I don't get why you have gpio-leds node, which is for >>>>> leds-gpio driver. >>>> Not sure I understood it right.. But if you are asking me why I have "leds {" and “gpio-leds” in there, then it is to get the entries in /sys/class/leds. >>>> The GPIOs from PCA9552 are connected to LED. Also, that is how we have had in the past, and that worked. >>>> Example: https://github.com/openbmc/linux/blob/dev-5.4/arch/arm/boot/dts/aspeed-bmc-opp-witherspoon.dts#L115 >>> >>> Thanks. Yeah, that looks OK, I had to take closer look at the driver. >>> >>>> The problem I am running into is for : https://github.com/openbmc/linux/blob/dev-5.4/arch/arm/boot/dts/aspeed-bmc-ibm-rainier.dts >>>>> >>>>> On 6/19/20 3:34 PM, Vishwanatha Subbanna wrote: >>>>>> Hello, >>>>>> I am Vishwanath, working with IBM and looking for your help on one of the issues that I am running into. Would really appreciate help on this. I run Linux 5.4.38 >>>>>> I have 2 number of PCA9552 chips, one on the Planar and other on the card that is optionally pluggable. The optional card must be plugged prior to booting and is not hot pluggable. In my experiment, I am running *without* the optional card plugged in. >>>>>> In the device tree, I have a "leds {" section that looks like below for the PCA9552 that is on the planar and everything works fine and I can see /sys/class/leds/fan0 >>>>>> leds { >>>>>> compatible = "gpio-leds”; >>>>>> fan0 { >>>>>> retain-state-shutdown; >>>>>> default-state = "keep"; >>>>>> gpios = <&pca0 0 GPIO_ACTIVE_LOW>; >>>>>> }; >>>>>> }; >>>>>> &i2c7 { >>>>>> status = "okay”; >>>>>> pca0: pca9552@61 { >>>>>> compatible = "nxp,pca9552"; >>>>>> reg = <0x61>; >>>>>> #address-cells = <1>; >>>>>> #size-cells = <0>; >>>>>> gpio-controller; >>>>>> #gpio-cells = <2>; >>>>>> gpio@0 { >>>>>> reg = <0>; >>>>>> type = ; >>>>>> }; >>>>>> }; >>>>>> }; >>>>>> Similarly, if I update the device tree entry for PCA9552 for the card that is optionally pluggable, then I don’t see any leds entries in /sys/class/leds. >>>>> >>>>> Please share your DT node after the update. >>>>> >>>> Pasting the GPIO_0 entry only here for brevity. >>>> leds { >>>> compatible = "gpio-leds”; >>>> fan0 { >>>> retain-state-shutdown; >>>> default-state = "keep"; >>>> gpios = <&pca0 0 GPIO_ACTIVE_LOW>; >>>> }; >>>> nvmeslot0 { >>>> retain-state-shutdown; >>>> default-state = "keep"; >>>> gpios = <&pca1 0 GPIO_ACTIVE_LOW>; >>>> }; >>>> }; >>>> &i2c7 { >>>> status = "okay”; >>>> pca0: pca9552@61 { >>>> compatible = "nxp,pca9552"; >>>> reg = <0x61>; >>>> #address-cells = <1>; >>>> #size-cells = <0>; >>>> gpio-controller; >>>> #gpio-cells = <2>; >>>> gpio@0 { >>>> reg = <0>; >>>> type = ; >>>> }; >>>> }; >>>> }; >>>> &i2c13 >>>> { >>>> pca1: pca9552@60 { >>>> compatible = "nxp,pca9552"; >>>> reg = <0x60>; >>>> #address-cells = <1>; >>>> #size-cells = <0>; >>>> gpio-controller; >>>> #gpio-cells = <2>; >>>> gpio@0 { >>>> reg = <0>; >>>> type = ; >>>> }; >>>> }; >>>> }; >>>> Thanks >>>> !! Vishwa !! >>>>>> I don’t even see “fan0” that is on the PCA9552 on planar also. I was expecting that I should see “/sys/class/leds/fan0”. >>>>>> However, I could see all the entries in “/proc/device-tree/leds”. >>>>>> Data from the failure. >>>>>> [ 7.895757] leds-pca955x 7-0061: leds-pca955x: Using pca9552 16-bit LED driver at slave address 0x61 >>>>>> [ 7.907659] leds-pca955x 7-0061: gpios 168...183 >>> >>> It is weird that you don't see "fan0" LED since this gpio seems to have >>> been properly registered according to this log. >>> >> This is exactly what I don’t understand. I would expect “fan0” to appear in /sys/class/leds. Is there any reason why this might not be appearing ?.. > > OK, now the reason is clear to me. If leds-gpio driver fails to register > any of the LEDs found in DT node it returns with an error from the > probe(), which results in unregistering any of the LEDs registered in > the previous iteration steps. > > Look at the function gpio_leds_create() in > drivers/leds/leds-gpio.c. > > Probably it is devm_fwnode_get_gpiod_from_child() that fails > while parsing nvmeslot0 node. Is this how it is designed or a bug ?.. From a system standpoint, not having an optional card results in not seeing the ones that are present on the system. Would you think it is worthwhile to modify to not chuck off what is existing because something optional is not plugged in ?.. I believe the I2C driver handles this scenario by putting an error message but still consumes what is present. > > -- > Best regards, > Jacek Anaszewski