From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: X-Spam-Checker-Version: SpamAssassin 3.4.0 (2014-02-07) on aws-us-west-2-korg-lkml-1.web.codeaurora.org X-Spam-Level: X-Spam-Status: No, score=-19.1 required=3.0 tests=BAYES_00,DKIMWL_WL_HIGH, DKIM_SIGNED,DKIM_VALID,DKIM_VALID_AU,HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_CR_TRAILER,INCLUDES_PATCH,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS, USER_AGENT_GIT autolearn=unavailable autolearn_force=no version=3.4.0 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 8C53BC433EF for ; Fri, 10 Sep 2021 12:31:20 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 74FFB611C0 for ; Fri, 10 Sep 2021 12:31:20 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S233325AbhIJMca (ORCPT ); Fri, 10 Sep 2021 08:32:30 -0400 Received: from mail.kernel.org ([198.145.29.99]:49638 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S233266AbhIJMc1 (ORCPT ); Fri, 10 Sep 2021 08:32:27 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 00DF1611C0; Fri, 10 Sep 2021 12:31:15 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1631277076; bh=6XbSVskJsOtrKyfNt70nuqspIS65v2VYg+YO2VhC85g=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=HtuauysLyn+2OQ8PojNgqa2/Hh0f98nIc9jNl/NAwZDcBXnaMJcDciS3UpYX7rrpI Tyz+g3p2H9lxll1oJsusPxC7+1LHuTspncrOEUYqPrjkkGs4RZkTDjl8nNd1AIg6If NmDh47DbiTLVEA4WBOTwf6Vy4lnRk9ic525zv5ew= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, DENG Qingfang , Sergio Paracuellos Subject: [PATCH 5.14 18/23] staging: mt7621-pci: fix hang when nothing is connected to pcie ports Date: Fri, 10 Sep 2021 14:30:08 +0200 Message-Id: <20210910122916.591587436@linuxfoundation.org> X-Mailer: git-send-email 2.33.0 In-Reply-To: <20210910122916.022815161@linuxfoundation.org> References: <20210910122916.022815161@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Precedence: bulk List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Sergio Paracuellos commit 7d761b084b3c785e1fbbe707fbdf7baba905c6ad upstream. When nothing is connected to pcie ports, each port is set to reset state. When this occurs, next access result in a hang on boot as follows: mt7621-pci 1e140000.pcie: pcie0 no card, disable it (RST & CLK) mt7621-pci 1e140000.pcie: pcie1 no card, disable it (RST & CLK) mt7621-pci 1e140000.pcie: pcie2 no card, disable it (RST & CLK) [ HANGS HERE ] Fix this just detecting 'nothing is connected state' to avoid next accesses to pcie port related configuration registers. Fixes: b99cc3a2b6b6 ("staging: mt7621-pci: avoid custom 'map_irq' function") Cc: stable Reported-by: DENG Qingfang Signed-off-by: Sergio Paracuellos Link: https://lore.kernel.org/r/20210823170803.2108-1-sergio.paracuellos@gmail.com Signed-off-by: Greg Kroah-Hartman --- drivers/staging/mt7621-pci/pci-mt7621.c | 13 +++++++++++-- 1 file changed, 11 insertions(+), 2 deletions(-) --- a/drivers/staging/mt7621-pci/pci-mt7621.c +++ b/drivers/staging/mt7621-pci/pci-mt7621.c @@ -56,6 +56,7 @@ #define PCIE_BAR_ENABLE BIT(0) #define PCIE_PORT_INT_EN(x) BIT(20 + (x)) #define PCIE_PORT_LINKUP BIT(0) +#define PCIE_PORT_CNT 3 #define PERST_DELAY_MS 100 @@ -388,10 +389,11 @@ static void mt7621_pcie_reset_ep_deasser msleep(PERST_DELAY_MS); } -static void mt7621_pcie_init_ports(struct mt7621_pcie *pcie) +static int mt7621_pcie_init_ports(struct mt7621_pcie *pcie) { struct device *dev = pcie->dev; struct mt7621_pcie_port *port, *tmp; + u8 num_disabled = 0; int err; mt7621_pcie_reset_assert(pcie); @@ -423,6 +425,7 @@ static void mt7621_pcie_init_ports(struc slot); mt7621_control_assert(port); port->enabled = false; + num_disabled++; if (slot == 0) { tmp = port; @@ -433,6 +436,8 @@ static void mt7621_pcie_init_ports(struc phy_power_off(tmp->phy); } } + + return (num_disabled != PCIE_PORT_CNT) ? 0 : -ENODEV; } static void mt7621_pcie_enable_port(struct mt7621_pcie_port *port) @@ -540,7 +545,11 @@ static int mt7621_pci_probe(struct platf return err; } - mt7621_pcie_init_ports(pcie); + err = mt7621_pcie_init_ports(pcie); + if (err) { + dev_err(dev, "Nothing connected in virtual bridges\n"); + return 0; + } err = mt7621_pcie_enable_ports(bridge); if (err) {