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 89A1AC433FE for ; Sat, 12 Nov 2022 20:10:33 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S231919AbiKLUKc (ORCPT ); Sat, 12 Nov 2022 15:10:32 -0500 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:38762 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233863AbiKLUKa (ORCPT ); Sat, 12 Nov 2022 15:10:30 -0500 X-Greylist: delayed 187 seconds by postgrey-1.37 at lindbergh.monkeyblade.net; Sat, 12 Nov 2022 12:10:29 PST Received: from mx-out.tlen.pl (mx-out.tlen.pl [193.222.135.145]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 74AF765E3 for ; Sat, 12 Nov 2022 12:10:28 -0800 (PST) Received: (wp-smtpd smtp.tlen.pl 18112 invoked from network); 12 Nov 2022 21:10:25 +0100 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=o2.pl; s=1024a; t=1668283825; bh=uqtOYyBZaSxTk6vFnxq67IjlDkClKoEOAUnHV1aUrT0=; h=From:To:Cc:Subject; b=FhnxMZy8l4sI4n3JMwI9GDByfbqZg8//i211z5MahGRACd3DKqmVMBsZ0BONJt2f0 yVX3tA8CGJkpBIwigre1BPdvyv0QNZjklYcsL4AQ+QWmqV6TMSGR69EBT7U/TZdPK+ s9iLLuzykfJTf1/yGZEw8R8eByS06fyS1Rhz330c= Received: from aaey149.neoplus.adsl.tpnet.pl (HELO localhost.localdomain) (mat.jonczyk@o2.pl@[83.4.128.149]) (envelope-sender ) by smtp.tlen.pl (WP-SMTPD) with SMTP for ; 12 Nov 2022 21:10:25 +0100 From: =?UTF-8?q?Mateusz=20Jo=C5=84czyk?= To: linux-kernel@vger.kernel.org, linux-pci@vger.kernel.org, linux-acpi@vger.kernel.org, linux-i2c@vger.kernel.org Cc: =?UTF-8?q?Mateusz=20Jo=C5=84czyk?= , Bjorn Helgaas , "Rafael J. Wysocki" , Len Brown , Borislav Petkov , Jean Delvare Subject: [PATCH] acpi,pci: warn about duplicate IRQ routing entries returned from _PRT Date: Sat, 12 Nov 2022 21:09:27 +0100 Message-Id: <20221112200927.7255-1-mat.jonczyk@o2.pl> X-Mailer: git-send-email 2.25.1 In-Reply-To: <35cfe433-bafa-9aeb-20ad-2f275f585b6c@o2.pl> References: <35cfe433-bafa-9aeb-20ad-2f275f585b6c@o2.pl> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit X-WP-MailID: 72f4d30cf4d363848074315d888fad29 X-WP-AV: skaner antywirusowy Poczty o2 X-WP-SPAM: NO 0000000 [UVOU] Precedence: bulk List-ID: X-Mailing-List: linux-acpi@vger.kernel.org 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. To check how widespread this problem is, print a warning to dmesg if this is the case. 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). After investigation, it turned out that the driver was using an incorrect interrupt vector: in lspci output for this device there was: Interrupt: pin B routed to IRQ 19 but after running i2cdetect (without using any i2c-i801 module parameters) the following was logged to dmesg: [...] i801_smbus 0000:00:1f.3: Timeout waiting for interrupt! i801_smbus 0000:00:1f.3: Transaction timeout irq 17: nobody cared (try booting with the "irqpoll" option) Existence of duplicate entries in the table returned by the _PRT method was confirmed by disassembling the ACPI DSDT table. Signed-off-by: Mateusz Jończyk Cc: Bjorn Helgaas Cc: "Rafael J. Wysocki" Cc: Len Brown Cc: Borislav Petkov Cc: Jean Delvare --- drivers/acpi/pci_irq.c | 25 ++++++++++++++++++++++--- 1 file changed, 22 insertions(+), 3 deletions(-) diff --git a/drivers/acpi/pci_irq.c b/drivers/acpi/pci_irq.c index 08e15774fb9f..c3168927446c 100644 --- a/drivers/acpi/pci_irq.c +++ b/drivers/acpi/pci_irq.c @@ -203,6 +203,8 @@ static int acpi_pci_irq_find_prt_entry(struct pci_dev *dev, struct acpi_buffer buffer = { ACPI_ALLOCATE_BUFFER, NULL }; struct acpi_pci_routing_table *entry; acpi_handle handle = NULL; + struct acpi_prt_entry *match = NULL; + const char *match_int_source = NULL; if (dev->bus->bridge) handle = ACPI_HANDLE(dev->bus->bridge); @@ -219,13 +221,30 @@ static int acpi_pci_irq_find_prt_entry(struct pci_dev *dev, entry = buffer.pointer; while (entry && (entry->length > 0)) { - if (!acpi_pci_irq_check_entry(handle, dev, pin, - entry, entry_ptr)) - break; + struct acpi_prt_entry *curr; + + if (!acpi_pci_irq_check_entry(handle, dev, pin, entry, &curr)) { + if (match == NULL) { + match = curr; + match_int_source = entry->source; + } else { + pr_warn(FW_BUG + "ACPI _PRT returned duplicate IRQ routing entries for device " + "%04x:%02x:%02x[INT%c]: %s[%d] and %s[%d]. ", + curr->id.segment, curr->id.bus, curr->id.device, + pin_name(curr->pin), + match_int_source, match->index, + entry->source, curr->index); + // we use the first matching entry nonetheless + } + } + entry = (struct acpi_pci_routing_table *) ((unsigned long)entry + entry->length); } + *entry_ptr = match; + kfree(buffer.pointer); return 0; } base-commit: f0c4d9fc9cc9462659728d168387191387e903cc -- 2.25.1