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=-8.5 required=3.0 tests=HEADER_FROM_DIFFERENT_DOMAINS, INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY,SPF_PASS,USER_AGENT_MUTT 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 ED79EC282CA for ; Wed, 13 Feb 2019 15:24:02 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id C4DAA222CD for ; Wed, 13 Feb 2019 15:24:02 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1727190AbfBMPX6 (ORCPT ); Wed, 13 Feb 2019 10:23:58 -0500 Received: from usa-sjc-mx-foss1.foss.arm.com ([217.140.101.70]:56056 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726139AbfBMPX5 (ORCPT ); Wed, 13 Feb 2019 10:23:57 -0500 Received: from usa-sjc-imap-foss1.foss.arm.com (unknown [10.72.51.249]) by usa-sjc-mx-foss1.foss.arm.com (Postfix) with ESMTP id 1756580D; Wed, 13 Feb 2019 07:23:57 -0800 (PST) Received: from e107981-ln.cambridge.arm.com (e107981-ln.cambridge.arm.com [10.1.197.40]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 6D60F3F575; Wed, 13 Feb 2019 07:23:55 -0800 (PST) Date: Wed, 13 Feb 2019 15:23:52 +0000 From: Lorenzo Pieralisi To: Bjorn Andersson Cc: Stanimir Varbanov , Bjorn Helgaas , linux-pci@vger.kernel.org, linux-arm-msm@vger.kernel.org, linux-kernel@vger.kernel.org, Khasim Syed Mohammed , Niklas Cassel , stable@vger.kernel.org Subject: Re: [PATCH] PCI: qcom: Don't deassert reset GPIO during probe Message-ID: <20190213152352.GB417@e107981-ln.cambridge.arm.com> References: <20190125232616.25714-1-bjorn.andersson@linaro.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20190125232616.25714-1-bjorn.andersson@linaro.org> User-Agent: Mutt/1.5.24 (2015-08-30) Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Fri, Jan 25, 2019 at 03:26:16PM -0800, Bjorn Andersson wrote: > Acquiring the reset GPIO low means that reset is being deasserted, this > is followed almost immediately with qcom_pcie_host_init() asserting it, > initializing it and then finally deasserting it again, for the link to > come up. > > Some PCIe devices requires a minimum time between the initial deassert > and subsequent reset cycles. In a platform that boots with the reset > GPIO asserted this requirement is being violated by this deassert/assert > pulse. > > Acquiring the reset GPIO high will prevent this by matching the state to > the subsequent asserted state. > > Cc: stable@vger.kernel.org Missing Fixes: tag, please provide me one so that I can proceed. Lorenzo > Signed-off-by: Bjorn Andersson > --- > drivers/pci/controller/dwc/pcie-qcom.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/pci/controller/dwc/pcie-qcom.c b/drivers/pci/controller/dwc/pcie-qcom.c > index d185ea5fe996..a7f703556790 100644 > --- a/drivers/pci/controller/dwc/pcie-qcom.c > +++ b/drivers/pci/controller/dwc/pcie-qcom.c > @@ -1228,7 +1228,7 @@ static int qcom_pcie_probe(struct platform_device *pdev) > > pcie->ops = of_device_get_match_data(dev); > > - pcie->reset = devm_gpiod_get_optional(dev, "perst", GPIOD_OUT_LOW); > + pcie->reset = devm_gpiod_get_optional(dev, "perst", GPIOD_OUT_HIGH); > if (IS_ERR(pcie->reset)) { > ret = PTR_ERR(pcie->reset); > goto err_pm_runtime_put; > -- > 2.18.0 >