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=-8.2 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 64948C3A59E for ; Mon, 2 Sep 2019 10:06:21 +0000 (UTC) Received: from bombadil.infradead.org (bombadil.infradead.org [198.137.202.133]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPS id 39F0F217D7 for ; Mon, 2 Sep 2019 10:06:21 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="ARvZJ80K" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 39F0F217D7 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=arm.com Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lists.infradead.org; s=bombadil.20170209; h=Sender: Content-Transfer-Encoding:Content-Type:Cc:List-Subscribe:List-Help:List-Post: List-Archive:List-Unsubscribe:List-Id:In-Reply-To:MIME-Version:References: Message-ID:Subject:To:From:Date:Reply-To:Content-ID:Content-Description: Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc:Resent-Message-ID: List-Owner; bh=cLpVzq5eTWCOoL2EQ5r255i5gnJ3SFTU42Cz8Iyuit0=; b=ARvZJ80KzKOpNn EcVUBDjLARsoySBKwJ8hCwk4xeiIJZJGkFTk/tRj3jEjL+a3MUP++zqcKAujtCf46wZHpBqdnQhvc JO33CAnaSWc469Bf29aCak7NvOhrLvVDxMBFhebhG1QV74TNZTC6MQBvG4rFznzeqmunyaxIl6Bs8 b1vWTaeNbzP92D8bvASRZ3k+v3sT+egHH8wIlUz2ND3VsZhGL5q05QqOV3l3xEeMEM+62WY3fJsuq /+RErcGgTnjEvBlRkJiBV4FNQEQEh82RSAz3qqWZqgr9iynQvmN8Y9xSX1j58onKPyKn+0XxhynrK 8K6MLz89s6UqSrAdOhwQ==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1i4jE4-00076L-Kk; Mon, 02 Sep 2019 10:06:20 +0000 Received: from foss.arm.com ([217.140.110.172]) by bombadil.infradead.org with esmtp (Exim 4.92 #3 (Red Hat Linux)) id 1i4jE1-00075S-RD for linux-arm-kernel@lists.infradead.org; Mon, 02 Sep 2019 10:06:19 +0000 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.121.207.14]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 2569328; Mon, 2 Sep 2019 03:06:15 -0700 (PDT) Received: from e121166-lin.cambridge.arm.com (unknown [10.1.196.255]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 3C8E73F246; Mon, 2 Sep 2019 03:06:14 -0700 (PDT) Date: Mon, 2 Sep 2019 11:06:11 +0100 From: Lorenzo Pieralisi To: Remi Pommarel , Thomas Petazzoni Subject: Re: [PATCH] PCI: aardvark: Don't rely on jiffies while holding spinlock Message-ID: <20190902100611.GB14841@e121166-lin.cambridge.arm.com> References: <20190901142303.27815-1-repk@triplefau.lt> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190901142303.27815-1-repk@triplefau.lt> User-Agent: Mutt/1.9.4 (2018-02-28) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190902_030617_930678_9CDFE78F X-CRM114-Status: GOOD ( 19.12 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Bjorn Helgaas , linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, linux-arm-kernel@lists.infradead.org Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: "linux-arm-kernel" Errors-To: linux-arm-kernel-bounces+infradead-linux-arm-kernel=archiver.kernel.org@lists.infradead.org On Sun, Sep 01, 2019 at 04:23:03PM +0200, Remi Pommarel wrote: > 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 > --- > drivers/pci/controller/pci-aardvark.c | 10 +++++----- > 1 file changed, 5 insertions(+), 5 deletions(-) Thomas, I would like to merge this patch and a couple of others from Remi, may I ask you please to review them ? https://patchwork.ozlabs.org/user/todo/linux-pci/?series=&submitter=67495&state=&q=&archive= Thanks, Lorenzo > diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c > index fc0fe4d4de49..1fa6d04ad7aa 100644 > --- a/drivers/pci/controller/pci-aardvark.c > +++ b/drivers/pci/controller/pci-aardvark.c > @@ -175,7 +175,8 @@ > (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 10 > +#define PIO_RETRY_DELAY 100 /* 100 us*/ > > #define LINK_WAIT_MAX_RETRIES 10 > #define LINK_WAIT_USLEEP_MIN 90000 > @@ -383,17 +384,16 @@ static void advk_pcie_check_pio_status(struct advk_pcie *pcie) > static int advk_pcie_wait_pio(struct advk_pcie *pcie) > { > struct device *dev = &pcie->pdev->dev; > - unsigned long timeout; > + size_t 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"); > -- > 2.20.1 > _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel