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 18D2CC433FE for ; Sat, 12 Nov 2022 20:14:04 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S230147AbiKLUOD (ORCPT ); Sat, 12 Nov 2022 15:14:03 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:39754 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S231252AbiKLUOC (ORCPT ); Sat, 12 Nov 2022 15:14:02 -0500 Received: from mx-out.tlen.pl (mx-out.tlen.pl [193.222.135.148]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 0DA05F5A7 for ; Sat, 12 Nov 2022 12:14:00 -0800 (PST) Received: (wp-smtpd smtp.tlen.pl 4821 invoked from network); 12 Nov 2022 21:07:16 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=o2.pl; s=1024a; t=1668283636; bh=loH1W2wKycWcNMDjsgektwUyaNDFHlHO5th0/v6bRmw=; h=Subject:To:Cc:From; b=egiq0jsRFmHMDiNfMFvMUBgqj5BDQ5X+lvuVFIyXA5M/rniZMizsr4bhOjx8FAWNN x6aZk2v6sI5h3RYl/cblVuoQhVgCnoq80vOEwkpxVdlz5GoMgtdppIQSjy/eXJTy4a U/sC2ojO2XaPvQnNq/dTUPWoFMxtaGLR3J1wULns= Received: from aaey149.neoplus.adsl.tpnet.pl (HELO [192.168.1.22]) (mat.jonczyk@o2.pl@[83.4.128.149]) (envelope-sender ) by smtp.tlen.pl (WP-SMTPD) with ECDHE-RSA-AES256-GCM-SHA384 encrypted SMTP for ; 12 Nov 2022 21:07:16 +0100 Message-ID: <35cfe433-bafa-9aeb-20ad-2f275f585b6c@o2.pl> Date: Sat, 12 Nov 2022 21:07:15 +0100 MIME-Version: 1.0 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:102.0) Gecko/20100101 Thunderbird/102.4.2 Subject: Re: [PATCH v2] acpi,pci: handle duplicate IRQ routing entries returned from _PRT To: Bjorn Helgaas , "Rafael J. Wysocki" Cc: linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-acpi@vger.kernel.org, Jonathan Corbet , Bjorn Helgaas , Len Brown , Borislav Petkov , Jean Delvare , linux-i2c@vger.kernel.org References: <20221112002023.GA764787@bhelgaas> Content-Language: en-GB From: =?UTF-8?Q?Mateusz_Jo=c5=84czyk?= In-Reply-To: <20221112002023.GA764787@bhelgaas> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-WP-MailID: 13e9072270332344864b56994e464f72 X-WP-AV: skaner antywirusowy Poczty o2 X-WP-SPAM: NO 0000000 [QbNF] Precedence: bulk List-ID: X-Mailing-List: linux-i2c@vger.kernel.org W dniu 12.11.2022 o 01:20, Bjorn Helgaas pisze: > [+cc Jean, linux-i2c] > > On Sat, Sep 17, 2022 at 11:09:44AM +0200, Mateusz Jończyk wrote: >> On some platforms, the ACPI _PRT function returns duplicate interrupt >> routing entries. Linux uses the first matching entry, but sometimes the >> second matching entry contains the correct interrupt vector. > Rafael, Jean, what do you think about this? It seems like kind of a > lot of infrastructure to deal with this oddness, but I'm not really > opposed to it. > > This is in i2c-i801.c, which seems to have some support for polling; > maybe it could make smart enough to complain and automatically switch > to polling if a timeout occurs. > > Or maybe we scan the entire _PRT and let the match win (instead of the > first as we do today). > > Or ...? > > Google finds a lot of hits for "i801_smbus" "timeout waiting for > interrupt", but I can't tell whether they're a similar _PRT issue or > something else. > >> This happens on a Dell Latitude E6500 laptop with the i2c-i801 Intel >> SMBus controller. This controller was nonfunctional unless its interrupt >> usage was disabled (using the "disable_features=0x10" module parameter). Hello, I have prepared a lean patch that only prints a warning when there are two matching entries in the table returned from _PRT (I will send it in the next e-mail). Perhaps it could be merged and then after a release or two it will be known how widespread this problem is. Greetings, Mateusz