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=-2.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_PASS,T_DKIMWL_WL_HIGH,USER_AGENT_MUTT autolearn=ham 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 6D8CAC43142 for ; Tue, 31 Jul 2018 11:13:23 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id 14375208A4 for ; Tue, 31 Jul 2018 11:13:23 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (1024-bit key) header.d=kernel.org header.i=@kernel.org header.b="bGiZKn6R" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 14375208A4 Authentication-Results: mail.kernel.org; dmarc=fail (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-kernel-owner@vger.kernel.org Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1731863AbeGaMxI (ORCPT ); Tue, 31 Jul 2018 08:53:08 -0400 Received: from mail.kernel.org ([198.145.29.99]:38586 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1729273AbeGaMxI (ORCPT ); Tue, 31 Jul 2018 08:53:08 -0400 Received: from localhost (unknown [69.71.4.100]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id 3A29020857; Tue, 31 Jul 2018 11:13:19 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1533035599; bh=Ta9mUt7JoXTn+MX98LaHbbt1IWNFTW2IT7A5DNowgb4=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=bGiZKn6Rx3sYDOQOlmobE1bUkEGUkFtM0gnCeQHie5zSLwmv0Pu3ifIxP0w+14Wij wqI5litrS1SlkykLSAxpv/WZ/jiVEWwvEl4sSZY+EdFigD7W0WbFX1b3KmeiV2Y71i 8W7/r5PS/CXa8H/Nlw0ntMzYIaABH3cXXRte0b+Y= Date: Tue, 31 Jul 2018 06:13:17 -0500 From: Bjorn Helgaas To: Russell King - ARM Linux Cc: Thomas Gleixner , Heiner Kallweit , Bjorn Helgaas , linux-pci@vger.kernel.org, Christoph Hellwig , linux-kernel@vger.kernel.org, MyungJoo Ham , Chanwoo Choi , Sebastian Reichel , Milo Kim , Krzysztof Kozlowski , Bartlomiej Zolnierkiewicz , Lee Jones Subject: Re: [PATCH] PCI: let pci_request_irq properly deal with threaded interrupts Message-ID: <20180731111317.GJ45322@bhelgaas-glaptop.roam.corp.google.com> References: <20180730213028.GC45322@bhelgaas-glaptop.roam.corp.google.com> <20180730224252.GE45322@bhelgaas-glaptop.roam.corp.google.com> <20180731080111.GG17271@n2100.armlinux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20180731080111.GG17271@n2100.armlinux.org.uk> User-Agent: Mutt/1.9.2 (2017-12-15) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Jul 31, 2018 at 09:01:12AM +0100, Russell King - ARM Linux wrote: > On Tue, Jul 31, 2018 at 12:50:21AM +0200, Thomas Gleixner wrote: > > On Mon, 30 Jul 2018, Bjorn Helgaas wrote: > > > > > [+cc maintainers of possibly erroneous callers of request_threaded_irq()] > > > > > > On Mon, Jul 30, 2018 at 04:30:28PM -0500, Bjorn Helgaas wrote: > > > > [+cc Thomas, Christoph, LKML] > > > > > > > > On Mon, Jul 30, 2018 at 12:03:42AM +0200, Heiner Kallweit wrote: > > > > > If we have a threaded interrupt with the handler being NULL, then > > > > > request_threaded_irq() -> __setup_irq() will complain and bail out > > > > > if the IRQF_ONESHOT flag isn't set. Therefore check for the handler > > > > > being NULL and set IRQF_ONESHOT in this case. > > > > > > > > > > This change is needed to migrate the mei_me driver to > > > > > pci_alloc_irq_vectors() and pci_request_irq(). > > > > > > > > > > Signed-off-by: Heiner Kallweit > > > > > > > > I'd like an ack from Thomas because this requirement about IRQF_ONESHOT > > > > usage isn't mentioned in the request_threaded_irq() function doc or > > > > Documentation/ > > > > > > Possibly these other request_threaded_irq() callers are similarly > > > broken? I can't tell for sure about tda998x_create(), but all the > > > others certainly call request_threaded_irq() with "handler == NULL" > > > and irqflags that do not contain IRQF_ONESHOT: > > > > > > tda998x_create() > > > request_threaded_irq(client->irq, NULL, ..., irqd_get_trigger_type(), ...) > > > (I can't tell what irqd_get_trigger_type() does) > > > > It reads the trigger type back from the irq chip (level/edge/polarity) but > > does not return with the ONESHOT bit set. > > What tree are you (Bjorn) using there? Looking in my git history, > request_threaded_irq() was added in January 2014, as: > > + irqf_trigger = > + irqd_get_trigger_type(irq_get_irq_data(client->irq)); > + ret = request_threaded_irq(client->irq, NULL, > + tda998x_irq_thread, > + irqf_trigger | IRQF_ONESHOT, > + "tda998x", priv); > > and updated more recently for the CEC support in ae81553c30ef > ("drm/i2c: tda998x: allow interrupt to be shared") to be: > > - irqf_trigger = > + irq_flags = > irqd_get_trigger_type(irq_get_irq_data(client->irq)); > + irq_flags |= IRQF_SHARED | IRQF_ONESHOT; > ret = request_threaded_irq(client->irq, NULL, > - tda998x_irq_thread, > - irqf_trigger | IRQF_ONESHOT, > + tda998x_irq_thread, irq_flags, > "tda998x", priv); > > In all cases, IRQF_ONESHOT has been set for this threaded interrupt. > > I've also checked drm-next, and it doesn't show anything like what > Bjorn quoted. > > Confused. Bjorn, can you double check that what you think are > erroneous request_threaded_irq() calls are actually as per what > you quoted please? I was looking at v4.18-rc1, but in the case of tda998x_create(), I overlooked this line: irq_flags |= IRQF_SHARED | IRQF_ONESHOT; Sorry!