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=-8.6 required=3.0 tests=DKIM_SIGNED,DKIM_VALID, DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS, USER_AGENT_MUTT autolearn=unavailable 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 2DC0EC10F03 for ; Mon, 25 Mar 2019 22:25:07 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id EEEC62082F for ; Mon, 25 Mar 2019 22:25:06 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553552707; bh=f+bXjXNI8BpHf9wMt6NcJ8eY+crxFfT1ppviPjRKvN8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=1+Wux1ZBO0Duglpn7EdtNDfuYjiTvPKFBKC7VNBTp5/7WIdbWT94ugNnm6KxRhu2M Rc/G6SljheVjuMrRaEb8lZf4vw/6njuiMuBPrZ6iPW+bit/UxOeGeBHC/BwLqavrzi l5ELEMg0HW69QkM4MbpevTD3TzODoe4IeK8AFx5U= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1730012AbfCYWZF (ORCPT ); Mon, 25 Mar 2019 18:25:05 -0400 Received: from mail.kernel.org ([198.145.29.99]:56468 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728912AbfCYWZF (ORCPT ); Mon, 25 Mar 2019 18:25:05 -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 909D220828; Mon, 25 Mar 2019 22:25:03 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1553552703; bh=f+bXjXNI8BpHf9wMt6NcJ8eY+crxFfT1ppviPjRKvN8=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=SVW+AcXTMWDwOWb1G3GGjIs50Fdyn97/RMHwmA7/UqyUSbYqURyoBeNvkCcInThfc JaclYyE3tw7FffoWm26sIhO0jHHsYfRtteaF2W/BOsz2ikVrmQNP11/PfkJFiCeL4P n2R7/fUlh+w1ycTr0CSdTpomEs9q5wCMHrBgyjrs= Date: Mon, 25 Mar 2019 17:25:02 -0500 From: Bjorn Helgaas To: Alexandru Gagniuc Cc: austin_bolen@dell.com, alex_gagniuc@dellteam.com, keith.busch@intel.com, Shyam_Iyer@Dell.com, lukas@wunner.de, okaya@kernel.org, torvalds@linux-foundation.org, linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org Subject: Re: [PATCH v2] PCI/LINK: bw_notification: Do not leave interrupt handler NULL Message-ID: <20190325222502.GC24180@google.com> References: <20190320193504.GC251185@google.com> <20190323003700.7294-1-mr.nuke.me@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190323003700.7294-1-mr.nuke.me@gmail.com> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: linux-kernel-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Mar 22, 2019 at 07:36:51PM -0500, Alexandru Gagniuc wrote: > A threaded IRQ with a NULL handler does not work with level-triggered > interrupts. request_threaded_irq() will return an error: > > genirq: Threaded irq requested with handler=NULL and !ONESHOT for irq 16 > pcie_bw_notification: probe of 0000:00:1b.0:pcie010 failed with error -22 > > For level interrupts we need to silence the interrupt before exiting > the IRQ handler, so just clear the PCI_EXP_LNKSTA_LBMS bit there. > > Fixes: e8303bb7a75c ("PCI/LINK: Report degraded links via link bandwidth notification") > Reported-by: Linus Torvalds > Signed-off-by: Alexandru Gagniuc Applied with the following subject line to for-linus for v5.1, thanks! PCI/LINK: Supply IRQ handler so level-triggered IRQs are acked > --- > Changes since v1: > - move pcie_update_link_speed() to irq to prevent duplicate read of link_status > - Add Fixes: to commit message > > drivers/pci/pcie/bw_notification.c | 19 ++++++++++++++----- > 1 file changed, 14 insertions(+), 5 deletions(-) > > diff --git a/drivers/pci/pcie/bw_notification.c b/drivers/pci/pcie/bw_notification.c > index d2eae3b7cc0f..c48746f1cf3c 100644 > --- a/drivers/pci/pcie/bw_notification.c > +++ b/drivers/pci/pcie/bw_notification.c > @@ -44,11 +44,10 @@ static void pcie_disable_link_bandwidth_notification(struct pci_dev *dev) > pcie_capability_write_word(dev, PCI_EXP_LNKCTL, lnk_ctl); > } > > -static irqreturn_t pcie_bw_notification_handler(int irq, void *context) > +static irqreturn_t pcie_bw_notification_irq(int irq, void *context) > { > struct pcie_device *srv = context; > struct pci_dev *port = srv->port; > - struct pci_dev *dev; > u16 link_status, events; > int ret; > > @@ -58,6 +57,17 @@ static irqreturn_t pcie_bw_notification_handler(int irq, void *context) > if (ret != PCIBIOS_SUCCESSFUL || !events) > return IRQ_NONE; > > + pcie_capability_write_word(port, PCI_EXP_LNKSTA, events); > + pcie_update_link_speed(port->subordinate, link_status); > + return IRQ_WAKE_THREAD; > +} > + > +static irqreturn_t pcie_bw_notification_handler(int irq, void *context) > +{ > + struct pcie_device *srv = context; > + struct pci_dev *port = srv->port; > + struct pci_dev *dev; > + > /* > * Print status from downstream devices, not this root port or > * downstream switch port. > @@ -67,8 +77,6 @@ static irqreturn_t pcie_bw_notification_handler(int irq, void *context) > __pcie_print_link_status(dev, false); > up_read(&pci_bus_sem); > > - pcie_update_link_speed(port->subordinate, link_status); > - pcie_capability_write_word(port, PCI_EXP_LNKSTA, events); > return IRQ_HANDLED; > } > > @@ -80,7 +88,8 @@ static int pcie_bandwidth_notification_probe(struct pcie_device *srv) > if (!pcie_link_bandwidth_notification_supported(srv->port)) > return -ENODEV; > > - ret = request_threaded_irq(srv->irq, NULL, pcie_bw_notification_handler, > + ret = request_threaded_irq(srv->irq, pcie_bw_notification_irq, > + pcie_bw_notification_handler, > IRQF_SHARED, "PCIe BW notif", srv); > if (ret) > return ret; > -- > 2.19.2 >