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 Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by smtp.lore.kernel.org (Postfix) with ESMTP id 7630FC77B7A for ; Thu, 25 May 2023 03:10:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S238026AbjEYDJ7 (ORCPT ); Wed, 24 May 2023 23:09:59 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:55286 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229459AbjEYDJ6 (ORCPT ); Wed, 24 May 2023 23:09:58 -0400 Received: from mail-pl1-x62f.google.com (mail-pl1-x62f.google.com [IPv6:2607:f8b0:4864:20::62f]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 45B3CA9 for ; Wed, 24 May 2023 20:09:57 -0700 (PDT) Received: by mail-pl1-x62f.google.com with SMTP id d9443c01a7336-1ae452c2777so3996275ad.0 for ; Wed, 24 May 2023 20:09:57 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gmail.com; s=20221208; t=1684984197; x=1687576197; h=content-disposition:mime-version:message-id:subject:cc:to:from:date :from:to:cc:subject:date:message-id:reply-to; bh=6VBxa9VXdZ/wJeHjNtU5vKbO+AGaRJNgDDgmpeETfoU=; b=o+wSkDHbH/eqPOvL9ip2XzzdOWkzmMcE9vTJOOX0U/fM1BPwNXBrtnDo8OymPFhpXR pYfmWhgFNdHKe2CW8VXT5M483emwSyBGqp5fLcVRzF6GPYY46XXnek07fAkN9KsELgoh C9TpdE3fc/X3Wrzsuk3Ohq3h6dRTirQEJws5LR9o8zxSrWl0/6VdSdBkDMfFVCtT+2p6 ZgFPZ6zFwfLr51+s5lPB49yJ2sm7Nu0xN94e9roRRKIO/zOMoF6XWYexHv9N4xghUHeN 8tXHKjC5syXwRXUk+ohVjRNYX4wqnWgpFeFo3V0pptrnxkTCSShAs4J9wNgh/6symsdD oK3A== X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20221208; t=1684984197; x=1687576197; h=content-disposition:mime-version:message-id:subject:cc:to:from:date :x-gm-message-state:from:to:cc:subject:date:message-id:reply-to; bh=6VBxa9VXdZ/wJeHjNtU5vKbO+AGaRJNgDDgmpeETfoU=; b=cURJ5Lz5KUn/KGpZmKdS2cPnScWSnlPKhc3NlswnIUylvCxXgj9ZcrfVMUH3XYKdpw 3Li+9n0VYmrq8egimzf936k1cO/EFVoib/LnOGprYX0HKTd7PJktq3Qlc+ihaUwGI/Ku pBkI0yJ6cLuPilUB3y3ivKddGj31yYP828KQARGF1oEfC5twjvYFlT7A2NjHIb2CH7GO G4e2jL7haDblOy3UHkEa5j/WwWFj/LSMVAXuC4bPBCCrJz7rKSpDTu57Wul1feHY26uw W7wsXUOb+aWCnhPLnupSy+1jEpfInS6TfYTTC4Y9OnoulOFH/e/4mGW3zZ/AGtmc+bL3 RzPA== X-Gm-Message-State: AC+VfDxK490WYnRXuuIZIj22iVklqdjRtfnO3b6ciR8NUpxG3ek9R0tE 2jWXM+Dcv1CUs83aJsf5yGMmUc1LY+E= X-Google-Smtp-Source: ACHHUZ4VIQc6aR4heOj/uhVA0ZAzTLDZtb7SxA3yynBlJSSAIowGC7tah7FCNqvnv3dgy+fcBRVl7g== X-Received: by 2002:a17:902:db0a:b0:1a2:a904:c42e with SMTP id m10-20020a170902db0a00b001a2a904c42emr94069plx.24.1684984196701; Wed, 24 May 2023 20:09:56 -0700 (PDT) Received: from sol (194-223-178-180.tpgi.com.au. [194.223.178.180]) by smtp.gmail.com with ESMTPSA id u2-20020a170902e5c200b001a9bcedd598sm200506plf.11.2023.05.24.20.09.54 (version=TLS1_3 cipher=TLS_AES_256_GCM_SHA384 bits=256/256); Wed, 24 May 2023 20:09:56 -0700 (PDT) Date: Thu, 25 May 2023 11:09:52 +0800 From: Kent Gibson To: brgl@bgdev.pl Cc: linux-gpio@vger.kernel.org Subject: [BUG] gpiolib: cdev: can't read RELEASED event for last line Message-ID: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Precedence: bulk List-ID: X-Mailing-List: linux-gpio@vger.kernel.org Hi Bart, In testing I'm finding that I can't read the RELEASED event from the chip fd when the last line on the chip is released. The chip fd becomes readable, but when I try to read it I get ENODEV. I suspect this change is the likely culprit: 533aae7c94db gpiolib: cdev: fix NULL-pointer dereferences @@ -2425,6 +2449,9 @@ static ssize_t lineinfo_watch_read(struct file *file, char __user *buf, int ret; size_t event_size; + if (!cdev->gdev->chip) + return -ENODEV; + though I haven't bisected it yet to be sure. Btw, that is testing on 6.4.0-rc3 mainline. Cheers, Kent.