From patchwork Sun Apr 2 11:12:59 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 8bit X-Patchwork-Submitter: "H. Nikolaus Schaller" X-Patchwork-Id: 669940 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 58E85C7619A for ; Sun, 2 Apr 2023 11:19:05 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229583AbjDBLTE (ORCPT ); Sun, 2 Apr 2023 07:19:04 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37880 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229447AbjDBLTD (ORCPT ); Sun, 2 Apr 2023 07:19:03 -0400 X-Greylist: delayed 346 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Sun, 02 Apr 2023 04:19:02 PDT Received: from mo4-p01-ob.smtp.rzone.de (mo4-p01-ob.smtp.rzone.de [85.215.255.51]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 86D261D2DC for ; Sun, 2 Apr 2023 04:19:02 -0700 (PDT) ARC-Seal: i=1; a=rsa-sha256; t=1680433980; cv=none; d=strato.com; s=strato-dkim-0002; b=SYastVuLe40ctMEpBc+3EC5HSgeIB+LitNtZaGybWM39JT6okEygDcQkWXwRiuv5Hj ePST8azQTVjkhZNpaN08HZOPUs3PX9qQEgGjir5sBOhfuYjLuoY8BBgq+1fzrJRMkgGh rcg5V+KWWRsgxv75xzADt+N8KuzKsDsL7lUPjsAo4NtfIWK8+pkwHmRR8WTTvUnxEOK1 9kw8ncONK6h+nn806oylqV5VdIH4IdJnTTdzVomAEMj9ckEdbeuJ9zyyo3CLVB48AUyD oV/4DberP64ZWOeLvpJ20jkG6Olasol2o0RVtUS7ztnhBvUi3+2QY4CMONa1uzr5C9+y iy7w== ARC-Message-Signature: i=1; a=rsa-sha256; c=relaxed/relaxed; t=1680433980; s=strato-dkim-0002; d=strato.com; h=Message-Id:Date:Subject:Cc:To:From:Cc:Date:From:Subject:Sender; bh=20X3HFLD0PCIwckyuLnAErqiyt22kmiUi0m0jrtysMQ=; b=QdsFMRDX6aki/NAkRUhqsBkanG+cQHP/HkcinRdvdr/RPJIWjdZxGu/qngOHy7wU0U RF9IMQO3z/ebFTWAAIPKrlhytyPa9ahmE+uMwkQ0vzF6Y2a+5LTbrRAxfvNnpZ3myb+N P5HZoVBtzq25IAl+xaWZz9xehItpCiTPUQDNLaCiioOVCQIdUuMPIh1Yq/8t7d2o04NY Sp/YyGvoyOoBvK+dqZ8JZ6uv/tPB+memyX8ThA6EwJHUDItX7EzT0k8c/ZdcAQAo1XQx eJmAzrooORkFvO4Q+YRhWJqgqNaO1wEVBS3/vFP6mrGJ42zAFoWNkSoByKNht0HXIDaj rW2Q== ARC-Authentication-Results: i=1; strato.com; arc=none; dkim=none X-RZG-CLASS-ID: mo01 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; t=1680433980; s=strato-dkim-0002; d=goldelico.com; h=Message-Id:Date:Subject:Cc:To:From:Cc:Date:From:Subject:Sender; bh=20X3HFLD0PCIwckyuLnAErqiyt22kmiUi0m0jrtysMQ=; b=K41SYxjIzYcgic5+TD9LYCtNs90pmQleRmBY3//U/qzuhpXAjedpumWGoV3J/CNMqG PIdi6Vi0u5vTDhrfzw8dJVJJgNUxHrFlMkonBsjfRFzukdYRRc9zH0D5jeZSFTIkGd+N XpguKMszMMvUcyBlWJiXXrPM2yWgVUqh0c/5TWEmus2HXH5vGZTDGCpI/6JPyvY9jGx9 +EJjcyRoCkMOD9lV2SFA+YSmw5cEWfmnyS3O6iSFGSLOP+lyVgqmxw8rFJTwZuv+LEtp 7q9oOjjT7qaO8z4T8iWCDh9KE6+25Q966tY2y78kMEK5atQYDfQRnvhc0x1P/f2OzzGl 1Opg== X-RZG-AUTH: ":JGIXVUS7cutRB/49FwqZ7WcJeFKiMhflhwDubTJ9o1iTDUhfN4hi3qVZq2PJ" Received: from iMac.fritz.box by smtp.strato.de (RZmta 49.3.1 DYNA|AUTH) with ESMTPSA id R24ce1z32BD0wL0 (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256 bits)) (Client did not present a certificate); Sun, 2 Apr 2023 13:13:00 +0200 (CEST) From: "H. Nikolaus Schaller" To: =?utf-8?q?Marek_Beh=C3=BAn?= , Pavel Machek , Lee Jones Cc: linux-leds@vger.kernel.org, linux-kernel@vger.kernel.org, letux-kernel@openphoenux.org, "H. Nikolaus Schaller" , NeilBrown , Linus Walleij Subject: [PATCH] leds: tca6507: fix error handling of using fwnode_property_read_string Date: Sun, 2 Apr 2023 13:12:59 +0200 Message-Id: X-Mailer: git-send-email 2.38.1 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-leds@vger.kernel.org Commit 96f524105b9c ("leds: tca6507: use fwnode API instead of OF") changed to fwnode API but did not take into account that a missing property "linux,default-trigger" now seems to return an error and as a side effect sets value to -1. This seems to be different from of_get_property() which always returned NULL in any case of error. Neglecting this side-effect leads to [ 11.201965] Unable to handle kernel paging request at virtual address ffffffff when read in the strcmp() of led_trigger_set_default() if there is no led-trigger defined in the DTS. I don't know if this was recently introduced somewhere in the fwnode lib or if the effect was missed in initial testing. Anyways it seems to be a bug to ignore the error return value of an optional value here in the driver. Fixes: 96f524105b9c ("leds: tca6507: use fwnode API instead of OF") Cc: Marek Behún Cc: NeilBrown Cc: Linus Walleij Signed-off-by: H. Nikolaus Schaller Acked-by: Pavel Machek --- drivers/leds/leds-tca6507.c | 5 +++-- 1 file changed, 3 insertions(+), 2 deletions(-) diff --git a/drivers/leds/leds-tca6507.c b/drivers/leds/leds-tca6507.c index 07dd12686a696..634cabd5bb796 100644 --- a/drivers/leds/leds-tca6507.c +++ b/drivers/leds/leds-tca6507.c @@ -691,8 +691,9 @@ tca6507_led_dt_init(struct device *dev) if (fwnode_property_read_string(child, "label", &led.name)) led.name = fwnode_get_name(child); - fwnode_property_read_string(child, "linux,default-trigger", - &led.default_trigger); + if (fwnode_property_read_string(child, "linux,default-trigger", + &led.default_trigger)) + led.default_trigger = NULL; led.flags = 0; if (fwnode_device_is_compatible(child, "gpio"))