From patchwork Mon Apr 2 16:21:59 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Keith Busch X-Patchwork-Id: 10320039 X-Patchwork-Delegate: bhelgaas@google.com Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork.web.codeaurora.org (Postfix) with ESMTP id 26C3560375 for ; Mon, 2 Apr 2018 16:20:01 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 1878020453 for ; Mon, 2 Apr 2018 16:20:01 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 0CEA0209D8; Mon, 2 Apr 2018 16:20:01 +0000 (UTC) X-Spam-Checker-Version: SpamAssassin 3.3.1 (2010-03-16) on pdx-wl-mail.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-6.9 required=2.0 tests=BAYES_00,RCVD_IN_DNSWL_HI autolearn=ham version=3.3.1 Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id A308820453 for ; Mon, 2 Apr 2018 16:20:00 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752572AbeDBQT6 (ORCPT ); Mon, 2 Apr 2018 12:19:58 -0400 Received: from mga11.intel.com ([192.55.52.93]:40106 "EHLO mga11.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752771AbeDBQT5 (ORCPT ); Mon, 2 Apr 2018 12:19:57 -0400 X-Amp-Result: SKIPPED(no attachment in message) X-Amp-File-Uploaded: False Received: from orsmga003.jf.intel.com ([10.7.209.27]) by fmsmga102.fm.intel.com with ESMTP/TLS/DHE-RSA-AES256-GCM-SHA384; 02 Apr 2018 09:19:56 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.48,396,1517904000"; d="scan'208";a="40113143" Received: from unknown (HELO localhost.lm.intel.com) ([10.232.112.44]) by orsmga003.jf.intel.com with ESMTP; 02 Apr 2018 09:19:56 -0700 From: Keith Busch To: Linux PCI , Bjorn Helgaas Cc: Oza Pawandeep , Sinan Kaya , Keith Busch Subject: [PATCHv2 3/7] PCI/DPC: Leave interrupts enabled while handling event Date: Mon, 2 Apr 2018 10:21:59 -0600 Message-Id: <20180402162203.3370-4-keith.busch@intel.com> X-Mailer: git-send-email 2.13.6 In-Reply-To: <20180402162203.3370-1-keith.busch@intel.com> References: <20180402162203.3370-1-keith.busch@intel.com> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org X-Virus-Scanned: ClamAV using ClamSMTP Now that the DPC driver clears the interrupt status before exiting the irq handler, we don't need to abuse the DPC control register to know if a shared interrupt is for a new DPC event: a DPC port can not trigger a second interrupt until the host clears the trigger status later in the work queue handler. Signed-off-by: Keith Busch --- drivers/pci/pcie/pcie-dpc.c | 24 +++++------------------- 1 file changed, 5 insertions(+), 19 deletions(-) diff --git a/drivers/pci/pcie/pcie-dpc.c b/drivers/pci/pcie/pcie-dpc.c index 82644245cb4d..38b2d0586c72 100644 --- a/drivers/pci/pcie/pcie-dpc.c +++ b/drivers/pci/pcie/pcie-dpc.c @@ -87,7 +87,7 @@ static void dpc_work(struct work_struct *work) struct dpc_dev *dpc = container_of(work, struct dpc_dev, work); struct pci_dev *dev, *temp, *pdev = dpc->dev->port; struct pci_bus *parent = pdev->subordinate; - u16 cap = dpc->cap_pos, ctl; + u16 cap = dpc->cap_pos; pci_lock_rescan_remove(); list_for_each_entry_safe_reverse(dev, temp, &parent->devices, @@ -113,10 +113,6 @@ static void dpc_work(struct work_struct *work) pci_write_config_word(pdev, cap + PCI_EXP_DPC_STATUS, PCI_EXP_DPC_STATUS_TRIGGER); - - pci_read_config_word(pdev, cap + PCI_EXP_DPC_CTL, &ctl); - pci_write_config_word(pdev, cap + PCI_EXP_DPC_CTL, - ctl | PCI_EXP_DPC_CTL_INT_EN); } static void dpc_process_rp_pio_error(struct dpc_dev *dpc) @@ -181,16 +177,10 @@ static irqreturn_t dpc_irq(int irq, void *context) struct dpc_dev *dpc = (struct dpc_dev *)context; struct pci_dev *pdev = dpc->dev->port; struct device *dev = &dpc->dev->device; - u16 cap = dpc->cap_pos, ctl, status, source, reason, ext_reason; - - pci_read_config_word(pdev, cap + PCI_EXP_DPC_CTL, &ctl); - - if (!(ctl & PCI_EXP_DPC_CTL_INT_EN) || ctl == (u16)(~0)) - return IRQ_NONE; + u16 cap = dpc->cap_pos, status, source, reason, ext_reason; pci_read_config_word(pdev, cap + PCI_EXP_DPC_STATUS, &status); - - if (!(status & PCI_EXP_DPC_STATUS_INTERRUPT)) + if (!(status & PCI_EXP_DPC_STATUS_INTERRUPT) || status == (u16)(~0)) return IRQ_NONE; if (!(status & PCI_EXP_DPC_STATUS_TRIGGER)) { @@ -199,9 +189,6 @@ static irqreturn_t dpc_irq(int irq, void *context) return IRQ_HANDLED; } - pci_write_config_word(pdev, cap + PCI_EXP_DPC_CTL, - ctl & ~PCI_EXP_DPC_CTL_INT_EN); - pci_read_config_word(pdev, cap + PCI_EXP_DPC_SOURCE_ID, &source); @@ -224,9 +211,8 @@ static irqreturn_t dpc_irq(int irq, void *context) pci_write_config_word(pdev, cap + PCI_EXP_DPC_STATUS, PCI_EXP_DPC_STATUS_INTERRUPT); - - schedule_work(&dpc->work); - + if (status & PCI_EXP_DPC_STATUS_TRIGGER) + schedule_work(&dpc->work); return IRQ_HANDLED; }