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=-2.1 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,FREEMAIL_FORGED_FROMDOMAIN,FREEMAIL_FROM, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_SANE_1 autolearn=no 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 32752C43603 for ; Wed, 4 Dec 2019 20:52:59 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id F09BD20656 for ; Wed, 4 Dec 2019 20:52:58 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com header.b="OoFLFYix" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1728078AbfLDUwz (ORCPT ); Wed, 4 Dec 2019 15:52:55 -0500 Received: from mail-wr1-f66.google.com ([209.85.221.66]:40581 "EHLO mail-wr1-f66.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1727889AbfLDUwz (ORCPT ); Wed, 4 Dec 2019 15:52:55 -0500 Received: by mail-wr1-f66.google.com with SMTP id c14so856015wrn.7; Wed, 04 Dec 2019 12:52:52 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20161025; h=subject:to:cc:references:from:autocrypt:message-id:date:user-agent :mime-version:in-reply-to:content-language:content-transfer-encoding; bh=wmCpBK5gKfNHkehfVw0oOjmIqfu20jWLSFxK7s8CnWs=; b=OoFLFYixY2AfF+VyBlD1cF+DZ1WKmEOtVBMCB2bN1SGSSXcy4gPFGq6Y+PQ+Mf8gOx bBPhTyIoib4LVgdjUIj203iTZu8rZJu8Kti0CbxNyEDIhKnSX6juMges8H5Ky+3xYKYi Q67yiqmRoulqT3mCJhWFCvrOVIhm46nQTt1bfDnpDAfJNW+3sX1Hq75ygzLL0oOf10GM bpTCFSPNK4UylN9uAHkVg9kkOx91aDeUMpUpytHJPrRgdnVtwRWV7BGpSNSTzI6nQXnY d9bvLDFVRbUBnktZ8lBsft1obFtaQan4u2r7l5voT/7GwCmErM8XNMYWSRP1ZaWPoBM6 jXaA== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:subject:to:cc:references:from:autocrypt :message-id:date:user-agent:mime-version:in-reply-to :content-language:content-transfer-encoding; bh=wmCpBK5gKfNHkehfVw0oOjmIqfu20jWLSFxK7s8CnWs=; b=PFp9+uu4KflPgvWdZ/iWXXKQWK6nxh3WmReaOChZQVrsSIjSaX0vo60WAOTOrVJaF+ 3vhWec41UNIZAK+4GLHa/jS8HPUWkrXjt1LJNI7nTE6rVq33ijXhpO5ZqCNu4mKEcQ2f lBsfseegnFCGlKsw7cyrVEl3Y70cGiZrQxVuinihFhaEtc+/LstQ5RKkSpcCZDk4Yjpc RRRMsqW5ps6qlKM70Vhqt6zjkzELIOaCp10lEfHzO8FJqGIbr3g/PNPSuFnv7NrarO7G KfnQ6wUIAVlpLpXNZZjiRVlzoHQvaIM4CPLaBNNay4Fn405CWPvFnJD4EYGUXXj3k+u6 8pZQ== X-Gm-Message-State: APjAAAUdEduq3uGeGIrjR4X7+lm6EiKwcGUK5INtQU+PhaL0XlnbCUYI JyzsI2yR3IQRz5MuYqHPLFdAFcoV X-Google-Smtp-Source: APXvYqx+bYv1DQGBl83+Eeq4X705HZYCFA6Q0ckfUXAI67YjcQ0weIWLFwYxBfNFLmS+7up1TSvWIA== X-Received: by 2002:a5d:6390:: with SMTP id p16mr6451840wru.170.1575492771741; Wed, 04 Dec 2019 12:52:51 -0800 (PST) Received: from [192.168.1.19] (cjl224.neoplus.adsl.tpnet.pl. [83.31.61.224]) by smtp.gmail.com with ESMTPSA id 188sm7707856wmz.13.2019.12.04.12.52.50 (version=TLS1_3 cipher=TLS_AES_128_GCM_SHA256 bits=128/128); Wed, 04 Dec 2019 12:52:51 -0800 (PST) Subject: Re: "leds: gpio: Use generic support for composing LED names" breaks gpio debugfs To: Russell King - ARM Linux admin , Linus Walleij , Pavel Machek Cc: linux-arm-kernel@lists.infradead.org, linux-leds@vger.kernel.org, linux-kernel@vger.kernel.org References: <20191204110219.GV25745@shell.armlinux.org.uk> From: Jacek Anaszewski Autocrypt: addr=jacek.anaszewski@gmail.com; prefer-encrypt=mutual; keydata= xsFNBFWjfaEBEADd66EQbd6yd8YjG0kbEDT2QIkx8C7BqMXR8AdmA1OMApbfSvEZFT1D/ECR eWFBS8XtApKQx1xAs1j5z70k3zebk2eeNs5ahxi6vM4Qh89vBM46biSKeeX5fLcv7asmGb/a FnHPAfQaKFyG/Bj9V+//ef67hpjJWR3s74C6LZCFLcbZM0z/wTH+baA5Jwcnqr4h/ygosvhP X3gkRzJLSFYekmEv+WHieeKXLrJdsUPUvPJTZtvi3ELUxHNOZwX2oRJStWpmL2QGMwPokRNQ 29GvnueQdQrIl2ylhul6TSrClMrKZqOajDFng7TLgvNfyVZE8WQwmrkTrdzBLfu3kScjE14Q Volq8OtQpTsw5570D4plVKh2ahlhrwXdneSot0STk9Dh1grEB/Jfw8dknvqkdjALUrrM45eF FM4FSMxIlNV8WxueHDss9vXRbCUxzGw37Ck9JWYo0EpcpcvwPf33yntYCbnt+RQRjv7vy3w5 osVwRR4hpbL/fWt1AnZ+RvbP4kYSptOCPQ+Pp1tCw16BOaPjtlqSTcrlD2fo2IbaB5D21SUa IsdZ/XkD+V2S9jCrN1yyK2iKgxtDoUkWiqlfRgH2Ep1tZtb4NLF/S0oCr7rNLO7WbqLZQh1q ShfZR16h7YW//1/NFwnyCVaG1CP/L/io719dPWgEd/sVSKT2TwARAQABzS1KYWNlayBBbmFz emV3c2tpIDxqYWNlay5hbmFzemV3c2tpQGdtYWlsLmNvbT7Cwa8EEwEIAEICGwMHCwkIBwMC AQYVCAIJCgsDFgIBAh4BAheABQkJZgNMFiEEvx38ClaPBfeVdXCQvWpQHLeLfCYFAl05/9sC GQEAIQkQvWpQHLeLfCYWIQS/HfwKVo8F95V1cJC9alAct4t8JqsxD/0U39aol03a1/rGQ/RE XJLh+3SxPTjOQ4IV84zGzyZn4pmgxT5fdr58SmkMvvGBEWkfIZoR6XuVKLV6q3OypnkmIdsN LUe3UbxO0BNvyryJ3ryp5J5baZ/NotD3w08QsZ9RcWhSpRCQbnPan3ZSsYXgy6PW84hb3enC 8Ti4Ok2yX6OuLAeiYu2MhShm0hGMZ9lELJRAjS+LktjNcJ5u7MCMYPsmHZgCnt8Mau/epOry xf4NQngf/4jw+Iv6NcqQR6mmoiGUEkmXhZyCCAy7dza6WNgO6pFiCG17fcFfII8Chx87b+w3 7IlFRNW5EWU7FSTiyvP9bxJAPA4DC0pXtPN3IXX+M4YHFbBLXcSMxvi7dfA8zNw+URA10irP vo0WYn33FgS+CQCYWZGKjG4FNG/wWzVzWNDTRZYnm97OpjqVxx0Oug9qVdZ4XN8+MiEptXcs BhOWq/Qi3vkZb37RMGE+p1MzXkOsJVcHtR6ztScPkUG1bB7BOfCv5y7y17jj1UMzM3Yj5r1g onWzq5mbOHkee4qfq0B8bJCHwy6NI4yVms0etGwiwtc6N4ZVrzhCT/Bq0Rw6jJDt35hpWixT Q4JmXQaV29sanXPa7xx3Y38cnt0CAWFDt20ZeZ1em3ZYpC9O9BeEisJZVASs1hsNkMPZXRNm 2U8Fpk/h+RQOS8f5LM4zBFsKioYWCSsGAQQB2kcPAQEHQFCKEG5pCgebryz66pTa9eAo+r8y TkMEEnG8UR5oWFt3wsIbBBgBCAAgFiEEvx38ClaPBfeVdXCQvWpQHLeLfCYFAlsKioYCGwIA rwkQvWpQHLeLfCaNIAQZFggAHRYhBBTDHErITmX+em3wBGIQbFEb9KXbBQJbCoqGACEJEGIQ bFEb9KXbFiEEFMMcSshOZf56bfAEYhBsURv0pdvELgD/U+y3/hsz0bIjMQJY0LLxM/rFY9Vz 1L43+lQHXjL3MPsA/1lNm5sailsY7aFBVJxAzTa8ZAGWBdVaGo6KCvimDB8GFiEEvx38ClaP BfeVdXCQvWpQHLeLfCbuOg/+PH6gY6Z1GiCzuYb/8f7D0NOcF8+md+R6KKiQZij/6G5Y7lXQ Bz21Opl4Vz/+39i5gmfBa9LRHH4ovR9Pd6H0FCjju4XjIOJkiJYs2HgCCm6nUxRJWzPgyMPS VbqCG2ctwaUiChUdbS+09bWb2MBNjIlI4b8wLWIOtxhyn25Vifm0p+QR5A2ym4bqJJ9LSre1 qM8qdPWcnExPFU4PZFYQgZ9pX1Jyui73ZUP94L7/wg1GyJZL3ePeE4ogBXldE0g0Wq3ORqA9 gA/yvrCSyNKOHTV9JMGnnPGN+wjBYMPMOuqDPC/zcK+stdFXc6UbUM1QNgDnaomvjuloflAx aYdblM26gFfypvpFb8czcPM+BP6X6vWk+Mw9+8vW3tyK9lSg+43OjIWlBGPpO9aLZsYYxAqv J5iSxcbbOLb5q8wWct6U7EZ1RnuOfVInoBttrlYvdWtcI/5NQTptkuB/DyRhrxBJc/fKzJ4w jS2ikcWe0FnxrQpcE2yqoUIFaZMdd/Cx9bRWAGZG087t5dUHJuMnVVcpHZFnHBKr8ag1eH/K tFdDFtyln5A/f9O22xsV0pyJni7e2z7lTBitrQFG69vnVGJlHbBE2dR4GddZqAlVOUbtEcE7 /aMk4TrCtx0IyOzQiLA81aaJWhkD3fRO8cDlR4YQ3F0aqjYy8x1EnnhhohHOwU0EVaN9oQEQ AMPNymBNoCWc13U6qOztXrIKBVsLGZXq/yOaR2n7gFbFACD0TU7XuH2UcnwvNR+uQFwSrRqa EczX2V6iIy2CITXKg5Yvg12yn09gTmafuoIyKoU16XvC3aZQQ2Bn3LO2sRP0j/NuMD9GlO37 pHCVRpI2DPxFE39TMm1PLbHnDG8+lZql+dpNwWw8dDaRgyXx2Le542CcTBT52VCeeWDtqd2M wOr4LioYlfGfAqmwcwucBdTEBUxklQaOR3VbJQx6ntI2oDOBlNGvjnVDzZe+iREd5l40l+Oj TaiWvBGXkv6OI+wx5TFPp+BM6ATU+6UzFRTUWbj+LqVA/JMqYHQp04Y4H5GtjbHCa8abRvBw IKEvpwTyWZlfXPtp8gRlNmxYn6gQlTyEZAWodXwE7CE+KxNnq7bPHeLvrSn8bLNK682PoTGr 0Y00bguYLfyvEwuDYek1/h9YSXtHaCR3CEj4LU1B561G1j7FVaeYbX9bKBAoy/GxAW8J5O1n mmw7FnkSHuwO/QDe0COoO0QZ620Cf9IBWYHW4m2M2yh5981lUaiMcNM2kPgsJFYloFo2XGn6 lWU9BrWjEoNDhHZtF+yaPEuwjZo6x/3E2Tu3E5Jj0VpVcE9U1Zq/fquDY79l2RJn5ENogOs5 +Pi0GjVpEYQVWfm0PTCxNPOzOzGR4QB3BNFvABEBAAHCwWUEGAEIAA8FAlWjfaECGwwFCQlm AYAACgkQvWpQHLeLfCZqGxAAlWBWVvjU6xj70GwengiqYZwmW1i8gfS4TNibQT/KRq0zkBnE wgKwXRbVoW38pYVuGa5x/JDQMJDrLAJ0wrCOS3XxbSHCWOl/k2ZD9OaxUeXq6N+OmGTzfrYv PUvWS1Hy04q9AD1dIaMNruZQmvnRfkOk2UDncDIg0166/NTHiYI09H5mpWGpHn/2aT6dmpVw uoM9/rHlF5s5qAAo95tZ0QW2BtIceG9/rbYlL57waSMPF49awvwLQX5RhWoF8mPS5LsBrXXK hmizIsn40tLbi2RtWjzDWgZYitqmmqijeCnDvISN4qJ/nCLO4DjiSGs59w5HR+l0nwePDhOC A4RYZqS1e2Clx1VSkDXFpL3egabcIsqK7CZ6a21r8lXVpo4RnMlQsmXZTnRx4SajFvX7PrRg /02C811fLfh2r5O5if8sKQ6BKKlHpuuioqfj/w9z3B0aQ71e4n1zNJBO1kcdznikPLAbr7jG gkBUXT1yJiwpTfRQr5y2Uo12IJsKxohnNFVYtK8X/R6S0deKPjrZWvAkllgIPcHjMi2Va8yw KTj/JgcpUO5KN906Pf7ywZISe7Kbcc/qnE0YjPPSqFOvoeZvHe6EZCMW9+xZsaipvlqpByQV UHnVg09K9YFvjUBsBPdC8ef6YwgfR9o6AnPmxl0oMUIXkCCC5c99fzJY/k8= Message-ID: Date: Wed, 4 Dec 2019 21:52:49 +0100 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:68.0) Gecko/20100101 Thunderbird/68.2.2 MIME-Version: 1.0 In-Reply-To: <20191204110219.GV25745@shell.armlinux.org.uk> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 8bit Sender: linux-leds-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-leds@vger.kernel.org Hi Russel, On 12/4/19 12:02 PM, Russell King - ARM Linux admin wrote: > Hi, > > Patch d7235f5feaa0 ("leds: gpio: Use generic support for composing LED > names") changed the way labels are used. > > devm_fwnode_get_gpiod_from_child() is passed led.name, which used to be > set to the label or node name, resulting in /sys/kernel/debug/gpio > containing useful information. For example: > > gpio-487 ( |udpu:green:power ) out lo > gpio-488 ( |udpu:red:power ) out hi > gpio-489 ( |udpu:green:network ) out hi > gpio-490 ( |udpu:red:network ) out hi > gpio-491 ( |udpu:green:alarm ) out hi > gpio-492 ( |udpu:red:alarm ) out hi > > After this commit, it now contains a rather less useful: > > gpio-487 ( |? ) out hi ACTIVE LOW > gpio-488 ( |? ) out hi ACTIVE LOW > gpio-489 ( |? ) out hi ACTIVE LOW > gpio-490 ( |? ) out hi ACTIVE LOW > gpio-491 ( |? ) out hi ACTIVE LOW > gpio-492 ( |? ) out hi ACTIVE LOW > > This is because led.name is now NULL prior to the call to > devm_fwnode_get_gpiod_from_child(). Ugh, my bad. But it actually has been wrong since the patch a96aa64cb5723 ("leds/led-class: Handle LEDs with the same name"), which enabled LED core to amend the LED name just beforehand the registration of a LED class device. It seem that the only proper solution would be introducing a new pre_register_cdev(const char *name) op to the LED core, that would allow drivers to come up with their implementation thereof. In this particular case leds-gpio driver would need to put there gpiod initialization. The pre_register_device op would need to be called (when available) from the led_classdev_register_ext() after calling led_classdev_next_name() and before device_create_with_groups(). The op would have to be passed the final_name variable then. > While this is not an API, it is useful for debugging, and given the > dynamic allocation of GPIOs to physical GPIOs, having the labels > present is an advantage. > > Can this be fixed / old behaviour restored? If there are no objections I can come up with a fix, but no sooner than at the weekend. -- Best regards, Jacek Anaszewski