From patchwork Sun Jun 11 17:19:57 2023 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "Maciej W. Rozycki" X-Patchwork-Id: 13275290 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 9B473C7EE23 for ; Sun, 11 Jun 2023 17:20:50 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233254AbjFKRUt (ORCPT ); Sun, 11 Jun 2023 13:20:49 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:45078 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S230233AbjFKRUs (ORCPT ); Sun, 11 Jun 2023 13:20:48 -0400 Received: from angie.orcam.me.uk (angie.orcam.me.uk [IPv6:2001:4190:8020::34]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 9B5ED199E; Sun, 11 Jun 2023 10:20:21 -0700 (PDT) Received: by angie.orcam.me.uk (Postfix, from userid 500) id E73559200C7; Sun, 11 Jun 2023 19:19:57 +0200 (CEST) Received: from localhost (localhost [127.0.0.1]) by angie.orcam.me.uk (Postfix) with ESMTP id E0F309200C0; Sun, 11 Jun 2023 18:19:57 +0100 (BST) Date: Sun, 11 Jun 2023 18:19:57 +0100 (BST) From: "Maciej W. Rozycki" To: Bjorn Helgaas , Mahesh J Salgaonkar , Oliver O'Halloran , Michael Ellerman , Nicholas Piggin , Christophe Leroy , Saeed Mahameed , Leon Romanovsky , "David S. Miller" , Eric Dumazet , Jakub Kicinski , Paolo Abeni cc: Alex Williamson , Lukas Wunner , Mika Westerberg , Stefan Roese , Jim Wilson , David Abdurachmanov , =?utf-8?q?Pali_Roh?= =?utf-8?q?=C3=A1r?= , linux-pci@vger.kernel.org, linuxppc-dev@lists.ozlabs.org, linux-rdma@vger.kernel.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org Subject: [PATCH v9 11/14] PCI: Use `pcie_wait_for_link_status' in `pcie_wait_for_link_delay' In-Reply-To: Message-ID: References: User-Agent: Alpine 2.21 (DEB 202 2017-01-01) MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: linux-rdma@vger.kernel.org Remove a DLLLA status bit polling loop from `pcie_wait_for_link_delay' and call almost identical code in `pcie_wait_for_link_status' instead. This reduces the lower bound on the polling interval from 10ms to 1ms, possibly increasing the CPU load on the system in favour to reducing the wait time. Signed-off-by: Maciej W. Rozycki --- New change in v9. --- drivers/pci/pci.c | 17 +++-------------- 1 file changed, 3 insertions(+), 14 deletions(-) linux-pcie-wait-for-link-delay-status.diff Index: linux-macro/drivers/pci/pci.c =================================================================== --- linux-macro.orig/drivers/pci/pci.c +++ linux-macro/drivers/pci/pci.c @@ -4889,16 +4889,14 @@ static bool pcie_wait_for_link_status(st static bool pcie_wait_for_link_delay(struct pci_dev *pdev, bool active, int delay) { - int timeout = PCIE_LINK_RETRAIN_TIMEOUT_MS; bool ret; - u16 lnk_status; /* * Some controllers might not implement link active reporting. In this * case, we wait for 1000 ms + any delay requested by the caller. */ if (!pdev->link_active_reporting) { - msleep(timeout + delay); + msleep(PCIE_LINK_RETRAIN_TIMEOUT_MS + delay); return true; } @@ -4913,20 +4911,11 @@ static bool pcie_wait_for_link_delay(str */ if (active) msleep(20); - for (;;) { - pcie_capability_read_word(pdev, PCI_EXP_LNKSTA, &lnk_status); - ret = !!(lnk_status & PCI_EXP_LNKSTA_DLLLA); - if (ret == active) - break; - if (timeout <= 0) - break; - msleep(10); - timeout -= 10; - } + ret = pcie_wait_for_link_status(pdev, false, active); if (active && ret) msleep(delay); - return ret == active; + return ret; } /**