From patchwork Tue May 3 21:46:24 2022 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Serge Semin X-Patchwork-Id: 12836389 X-Patchwork-Delegate: lorenzo.pieralisi@arm.com 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 9767CC4167B for ; Tue, 3 May 2022 21:47:07 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S243155AbiECVui (ORCPT ); Tue, 3 May 2022 17:50:38 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:60864 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S243086AbiECVug (ORCPT ); Tue, 3 May 2022 17:50:36 -0400 Received: from mail.baikalelectronics.ru (mail.baikalelectronics.com [87.245.175.226]) by lindbergh.monkeyblade.net (Postfix) with ESMTP id 03C1E205DE; Tue, 3 May 2022 14:47:02 -0700 (PDT) Received: from mail.baikalelectronics.ru (unknown [192.168.51.25]) by mail.baikalelectronics.ru (Postfix) with ESMTP id 0A27016D7; Wed, 4 May 2022 00:47:36 +0300 (MSK) DKIM-Filter: OpenDKIM Filter v2.11.0 mail.baikalelectronics.ru 0A27016D7 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=baikalelectronics.ru; s=mail; t=1651614456; bh=WAWRREuBpnxzwPhyspvE7nalemSfsPDWPJynnF5ccvY=; h=From:To:CC:Subject:Date:In-Reply-To:References:From; b=abS7G0LPiC870qVwy/aUM+jaAGLW/W7WTDGm/TVyf6EVFQOIBHkkN3k1XsHTXIvbm p/9DtajXElTg8CfK9dmBOW48isnNuMi308yZpRHVwHgcf22DWp6iVwfeqe8L961IGj wahiQ4jT18ev2PjU2lZjukBl5o+ilyB03j4iPuF8= Received: from localhost (192.168.53.207) by mail (192.168.51.25) with Microsoft SMTP Server (TLS) id 15.0.1395.4; Wed, 4 May 2022 00:47:02 +0300 From: Serge Semin To: Jingoo Han , Gustavo Pimentel , Bjorn Helgaas , Lorenzo Pieralisi , Rob Herring , =?utf-8?q?Krzysztof_Wilczy=C5=84ski?= CC: Serge Semin , Serge Semin , Alexey Malahov , Pavel Parkhomenko , Frank Li , Manivannan Sadhasivam , Rob Herring , , , Subject: [PATCH v2 03/17] PCI: dwc: Add more verbose link-up message Date: Wed, 4 May 2022 00:46:24 +0300 Message-ID: <20220503214638.1895-4-Sergey.Semin@baikalelectronics.ru> In-Reply-To: <20220503214638.1895-1-Sergey.Semin@baikalelectronics.ru> References: <20220503214638.1895-1-Sergey.Semin@baikalelectronics.ru> MIME-Version: 1.0 X-ClientProxiedBy: MAIL.baikal.int (192.168.51.25) To mail (192.168.51.25) Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org Printing just "link up" isn't that much informative especially when it comes to working with the PCI Express bus. Even if the link is up, due to multiple reasons the bus performance can degrade to slower speeds or to narrower width than both Root Port and its partner is capable of. In that case it would be handy to know the link specifications as early as possible. So let's add a more verbose message to the busy-wait link-state method, which will contain the link speed generation and the PCIe bus width in case if the link up state is discovered. Otherwise an error will be printed to the system log. Signed-off-by: Serge Semin Reviewed-by: Rob Herring --- Changelog v2: - Test the error condition first and return straight away if it comes true. The typical return is better to be unindented (@Joe). --- drivers/pci/controller/dwc/pcie-designware.c | 22 ++++++++++++++------ 1 file changed, 16 insertions(+), 6 deletions(-) diff --git a/drivers/pci/controller/dwc/pcie-designware.c b/drivers/pci/controller/dwc/pcie-designware.c index 6e81264fdfb4..1682f477bf20 100644 --- a/drivers/pci/controller/dwc/pcie-designware.c +++ b/drivers/pci/controller/dwc/pcie-designware.c @@ -524,20 +524,30 @@ void dw_pcie_disable_atu(struct dw_pcie *pci, int index, int dw_pcie_wait_for_link(struct dw_pcie *pci) { + u32 offset, val; int retries; /* Check if the link is up or not */ for (retries = 0; retries < LINK_WAIT_MAX_RETRIES; retries++) { - if (dw_pcie_link_up(pci)) { - dev_info(pci->dev, "Link up\n"); - return 0; - } + if (dw_pcie_link_up(pci)) + break; + usleep_range(LINK_WAIT_USLEEP_MIN, LINK_WAIT_USLEEP_MAX); } - dev_info(pci->dev, "Phy link never came up\n"); + if (retries >= LINK_WAIT_MAX_RETRIES) { + dev_err(pci->dev, "Phy link never came up\n"); + return -ETIMEDOUT; + } + + offset = dw_pcie_find_capability(pci, PCI_CAP_ID_EXP); + val = dw_pcie_readw_dbi(pci, offset + PCI_EXP_LNKSTA); - return -ETIMEDOUT; + dev_info(pci->dev, "PCIe Gen.%u x%u link up\n", + FIELD_GET(PCI_EXP_LNKSTA_CLS, val), + FIELD_GET(PCI_EXP_LNKSTA_NLW, val)); + + return 0; } EXPORT_SYMBOL_GPL(dw_pcie_wait_for_link);