From patchwork Mon Jul 19 14:52:12 2021 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: "gregkh@linuxfoundation.org" X-Patchwork-Id: 480947 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=-20.2 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=ham 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 E2A46C07E9B for ; Mon, 19 Jul 2021 15:43:43 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id D19C46113A for ; Mon, 19 Jul 2021 15:43:43 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1343603AbhGSPDB (ORCPT ); Mon, 19 Jul 2021 11:03:01 -0400 Received: from mail.kernel.org ([198.145.29.99]:59498 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S245503AbhGSPAq (ORCPT ); Mon, 19 Jul 2021 11:00:46 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 8E543611CE; Mon, 19 Jul 2021 15:41:25 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=linuxfoundation.org; s=korg; t=1626709286; bh=WGzptOHDB9unVbKzEhatZhYRDd6ORQ6iqyQkfmJuuQ8=; h=From:To:Cc:Subject:Date:In-Reply-To:References:From; b=ep8TLlRdBFkL5w4lyIAKkPzh9kAGG+59rKNY7dxAtfKSx2pFEnFrRxG1PVbgOkXyG YJu9SNij7eH8Nw1OYCep+oy1eCki5QrbLNt1QEbo6+YrVdXbm8479JSWF5Kt+cRcGi jr5/FNCffuf1X41rSzOuz8T5d/J0mvQYwlzHlYR0= From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Remi Pommarel , Lorenzo Pieralisi , Andrew Murray , Thomas Petazzoni Subject: [PATCH 4.19 321/421] PCI: aardvark: Dont rely on jiffies while holding spinlock Date: Mon, 19 Jul 2021 16:52:12 +0200 Message-Id: <20210719144957.433531856@linuxfoundation.org> X-Mailer: git-send-email 2.32.0 In-Reply-To: <20210719144946.310399455@linuxfoundation.org> References: <20210719144946.310399455@linuxfoundation.org> User-Agent: quilt/0.66 MIME-Version: 1.0 Precedence: bulk List-ID: X-Mailing-List: stable@vger.kernel.org From: Remi Pommarel commit 7fbcb5da811be7d47468417c7795405058abb3da upstream. advk_pcie_wait_pio() can be called while holding a spinlock (from pci_bus_read_config_dword()), then depends on jiffies in order to timeout while polling on PIO state registers. In the case the PIO transaction failed, the timeout will never happen and will also cause the cpu to stall. This decrements a variable and wait instead of using jiffies. Signed-off-by: Remi Pommarel Signed-off-by: Lorenzo Pieralisi Reviewed-by: Andrew Murray Acked-by: Thomas Petazzoni Signed-off-by: Greg Kroah-Hartman --- drivers/pci/controller/pci-aardvark.c | 10 +++++----- 1 file changed, 5 insertions(+), 5 deletions(-) --- a/drivers/pci/controller/pci-aardvark.c +++ b/drivers/pci/controller/pci-aardvark.c @@ -166,7 +166,8 @@ (PCIE_CONF_BUS(bus) | PCIE_CONF_DEV(PCI_SLOT(devfn)) | \ PCIE_CONF_FUNC(PCI_FUNC(devfn)) | PCIE_CONF_REG(where)) -#define PIO_TIMEOUT_MS 1 +#define PIO_RETRY_CNT 500 +#define PIO_RETRY_DELAY 2 /* 2 us*/ #define LINK_WAIT_MAX_RETRIES 10 #define LINK_WAIT_USLEEP_MIN 90000 @@ -369,17 +370,16 @@ static void advk_pcie_check_pio_status(s static int advk_pcie_wait_pio(struct advk_pcie *pcie) { struct device *dev = &pcie->pdev->dev; - unsigned long timeout; + int i; - timeout = jiffies + msecs_to_jiffies(PIO_TIMEOUT_MS); - - while (time_before(jiffies, timeout)) { + for (i = 0; i < PIO_RETRY_CNT; i++) { u32 start, isr; start = advk_readl(pcie, PIO_START); isr = advk_readl(pcie, PIO_ISR); if (!start && isr) return 0; + udelay(PIO_RETRY_DELAY); } dev_err(dev, "config read/write timed out\n");