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: 1793645 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@legolas.ozlabs.org Authentication-Results: legolas.ozlabs.org; spf=pass (sender SPF authorized) smtp.mailfrom=lists.ozlabs.org (client-ip=2404:9400:2:0:216:3eff:fee1:b9f1; helo=lists.ozlabs.org; envelope-from=linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org; receiver=) Received: from lists.ozlabs.org (lists.ozlabs.org [IPv6:2404:9400:2:0:216:3eff:fee1:b9f1]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature ECDSA (P-384)) (No client certificate requested) by legolas.ozlabs.org (Postfix) with ESMTPS id 4QfMBf1lZ5z20Vx for ; Mon, 12 Jun 2023 03:24:41 +1000 (AEST) Received: from boromir.ozlabs.org (localhost [IPv6:::1]) by lists.ozlabs.org (Postfix) with ESMTP id 4QfMBd4Vycz3clT for ; Mon, 12 Jun 2023 03:24:41 +1000 (AEST) X-Original-To: linuxppc-dev@lists.ozlabs.org Delivered-To: linuxppc-dev@lists.ozlabs.org Authentication-Results: lists.ozlabs.org; spf=none (no SPF record) smtp.mailfrom=orcam.me.uk (client-ip=78.133.224.34; helo=angie.orcam.me.uk; envelope-from=macro@orcam.me.uk; receiver=lists.ozlabs.org) Received: from angie.orcam.me.uk (angie.orcam.me.uk [78.133.224.34]) by lists.ozlabs.org (Postfix) with ESMTP id 4QfM5C3Czdz2y1W for ; Mon, 12 Jun 2023 03:19:59 +1000 (AEST) 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 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 X-BeenThere: linuxppc-dev@lists.ozlabs.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Linux on PowerPC Developers Mail List List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: =?utf-8?q?Pali_Roh=C3=A1r?= , David Abdurachmanov , linux-rdma@vger.kernel.org, Mika Westerberg , linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Alex Williamson , Lukas Wunner , linux-pci@vger.kernel.org, Stefan Roese , Jim Wilson , netdev@vger.kernel.org Errors-To: linuxppc-dev-bounces+incoming=patchwork.ozlabs.org@lists.ozlabs.org Sender: "Linuxppc-dev" 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; } /**