From patchwork Wed Feb 20 16:33:54 2019 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Srinath Mannam X-Patchwork-Id: 10822489 Return-Path: Received: from mail.wl.linuxfoundation.org (pdx-wl-mail.web.codeaurora.org [172.30.200.125]) by pdx-korg-patchwork-2.web.codeaurora.org (Postfix) with ESMTP id B7CE317E9 for ; Wed, 20 Feb 2019 16:34:13 +0000 (UTC) Received: from mail.wl.linuxfoundation.org (localhost [127.0.0.1]) by mail.wl.linuxfoundation.org (Postfix) with ESMTP id 9FCC42C1F0 for ; Wed, 20 Feb 2019 16:34:13 +0000 (UTC) Received: by mail.wl.linuxfoundation.org (Postfix, from userid 486) id 93B9F2C2F6; Wed, 20 Feb 2019 16:34:13 +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=-8.0 required=2.0 tests=BAYES_00,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,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 317822C1F0 for ; Wed, 20 Feb 2019 16:34:13 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726377AbfBTQeM (ORCPT ); Wed, 20 Feb 2019 11:34:12 -0500 Received: from mail-pl1-f193.google.com ([209.85.214.193]:41970 "EHLO mail-pl1-f193.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725822AbfBTQeL (ORCPT ); Wed, 20 Feb 2019 11:34:11 -0500 Received: by mail-pl1-f193.google.com with SMTP id y5so6906259plk.8 for ; Wed, 20 Feb 2019 08:34:11 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=broadcom.com; s=google; h=from:to:cc:subject:date:message-id:in-reply-to:references; bh=5JMpbtJFok6NmyP09wHWoeTClnCNAZoek3gSUOSs3x0=; b=RmlccQeCYowaxbJ7ccWoPEOLRf/t0oWGtdbuaYzv+WOyd9XtLfEjlHPhzZT9uyTbsy ZMB4mcyyQn/rwdJnS5z3g6L6BxV/EdbgUBowBsNpsUH5zS3JouwtPVvIi8QXrp5+BIQq hNf1+ASiQ2Z1/AYpTJBwW2GP83LFjCRPr39s8= X-Google-DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=1e100.net; s=20161025; h=x-gm-message-state:from:to:cc:subject:date:message-id:in-reply-to :references; bh=5JMpbtJFok6NmyP09wHWoeTClnCNAZoek3gSUOSs3x0=; b=iVosczbuqEjj55ITEXBiYe/p2OScGFNirrEWtRDypGOS7RY/hTa+J+TCmXUXSK+Gnt CI4e7rrC9RAnrmS3MYvMKEQstMCH8UKK1vEKGYFXrtNLPrcm+1zGsBFxXub3Un4AIObD 3f7iZujbcXNrkkov+dU2cDGNqscpQS9KNJzOdjWv1xTSP7Vzv0hYgHn+z3FVlfDOjdCD PTmdVacow4thDymH17sFaoKHglAy4nfuaLo06qGYzGvpO8eaOIsWlcGgEC7VAyOBmnZs Bw7WZg9zBRCMAF8hCyGV8qO6rGvCAF4S89rbslu2Pm9nSIge2Vla9uSCddg8Rf6NdBxf 9B0Q== X-Gm-Message-State: AHQUAuYe1pWfYnRh42BK/1xqHZo8CjqS23AuaBbVRhspim44MjpoTHiQ W6DOLeR69dgG2dQS+ctwmaM/XA== X-Google-Smtp-Source: AHgI3IY8WjyHVjXGBqE+g1rHOxfoj6OPgU0zvCl8moah1jJaqkXrjklULWWDfZcULwCmIUPaJhEeVg== X-Received: by 2002:a17:902:6b4b:: with SMTP id g11mr36696005plt.92.1550680451148; Wed, 20 Feb 2019 08:34:11 -0800 (PST) Received: from mannams-OptiPlex-7010.dhcp.broadcom.net ([192.19.234.250]) by smtp.gmail.com with ESMTPSA id t10sm26556717pfa.151.2019.02.20.08.34.07 (version=TLS1_2 cipher=ECDHE-RSA-AES128-SHA bits=128/128); Wed, 20 Feb 2019 08:34:10 -0800 (PST) From: Srinath Mannam To: Bjorn Helgaas , Lorenzo Pieralisi , Ray Jui , Scott Branden Cc: bcm-kernel-feedback-list@broadcom.com, linux-pci@vger.kernel.org, linux-arm-kernel@lists.infradead.org, linux-kernel@vger.kernel.org, Srinath Mannam Subject: [PATCH v3 1/2] PCI: iproc: Add CRS check in config read Date: Wed, 20 Feb 2019 22:03:54 +0530 Message-Id: <1550680435-9706-2-git-send-email-srinath.mannam@broadcom.com> X-Mailer: git-send-email 2.7.4 In-Reply-To: <1550680435-9706-1-git-send-email-srinath.mannam@broadcom.com> References: <1550680435-9706-1-git-send-email-srinath.mannam@broadcom.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 In the current implementation, config read output data 0xffff0001 is assumed as CRS completion. But sometimes 0xffff0001 can be a valid data. IPROC PCIe host controller PAXB v2 has a register to show config read status flags like SC, UR, CRS and CA. So that extra check is added to confirm the CRS using status flags before reissue config read. Signed-off-by: Srinath Mannam Reviewed-by: Ray Jui --- drivers/pci/controller/pcie-iproc.c | 23 +++++++++++++++++++++-- 1 file changed, 21 insertions(+), 2 deletions(-) diff --git a/drivers/pci/controller/pcie-iproc.c b/drivers/pci/controller/pcie-iproc.c index c20fd6b..b882255 100644 --- a/drivers/pci/controller/pcie-iproc.c +++ b/drivers/pci/controller/pcie-iproc.c @@ -60,6 +60,10 @@ #define APB_ERR_EN_SHIFT 0 #define APB_ERR_EN BIT(APB_ERR_EN_SHIFT) +#define CFG_RD_SUCCESS 0 +#define CFG_RD_UR 1 +#define CFG_RD_CRS 2 +#define CFG_RD_CA 3 #define CFG_RETRY_STATUS 0xffff0001 #define CFG_RETRY_STATUS_TIMEOUT_US 500000 /* 500 milliseconds */ @@ -289,6 +293,9 @@ enum iproc_pcie_reg { IPROC_PCIE_IARR4, IPROC_PCIE_IMAP4, + /* config read status */ + IPROC_PCIE_CFG_RD_STATUS, + /* link status */ IPROC_PCIE_LINK_STATUS, @@ -350,6 +357,7 @@ static const u16 iproc_pcie_reg_paxb_v2[] = { [IPROC_PCIE_IMAP3] = 0xe08, [IPROC_PCIE_IARR4] = 0xe68, [IPROC_PCIE_IMAP4] = 0xe70, + [IPROC_PCIE_CFG_RD_STATUS] = 0xee0, [IPROC_PCIE_LINK_STATUS] = 0xf0c, [IPROC_PCIE_APB_ERR_EN] = 0xf40, }; @@ -474,10 +482,12 @@ static void __iomem *iproc_pcie_map_ep_cfg_reg(struct iproc_pcie *pcie, return (pcie->base + offset); } -static unsigned int iproc_pcie_cfg_retry(void __iomem *cfg_data_p) +static unsigned int iproc_pcie_cfg_retry(struct iproc_pcie *pcie, + void __iomem *cfg_data_p) { int timeout = CFG_RETRY_STATUS_TIMEOUT_US; unsigned int data; + u32 status; /* * As per PCIe spec r3.1, sec 2.3.2, CRS Software Visibility only @@ -498,6 +508,15 @@ static unsigned int iproc_pcie_cfg_retry(void __iomem *cfg_data_p) */ data = readl(cfg_data_p); while (data == CFG_RETRY_STATUS && timeout--) { + /* + * CRS state is set in CFG_RD status register + * This will handle the case where CFG_RETRY_STATUS is + * valid config data. + */ + status = iproc_pcie_read_reg(pcie, IPROC_PCIE_CFG_RD_STATUS); + if (status != CFG_RD_CRS) + return data; + udelay(1); data = readl(cfg_data_p); } @@ -576,7 +595,7 @@ static int iproc_pcie_config_read(struct pci_bus *bus, unsigned int devfn, if (!cfg_data_p) return PCIBIOS_DEVICE_NOT_FOUND; - data = iproc_pcie_cfg_retry(cfg_data_p); + data = iproc_pcie_cfg_retry(pcie, cfg_data_p); *val = data; if (size <= 2)