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=-8.6 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,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 3FDF8C2BA1A for ; Fri, 24 Apr 2020 09:25:50 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1B4B22074F for ; Fri, 24 Apr 2020 09:25:50 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587720350; bh=t7xTZ9J4en/MjkiMHZhzp48oDSHJbtjCC8DX8NgHS6k=; h=Date:From:To:Cc:Subject:References:In-Reply-To:List-ID:From; b=KbZnkajCjNDlZ0NRPLbu2jv080KOIXwMS2luTXxfDxZ7JOD8hAW2tu+vPmhy94vhN f6aWBVowYbS3kgLkmi6npjbgRMYhljL7l2iRe1zxaBItUU0olyfEtFyHILY3OGHEbI 0J6ItC74M+pLIeb6zumQMP8mY8Rcc9CNxLC9+ulk= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726347AbgDXJZt (ORCPT ); Fri, 24 Apr 2020 05:25:49 -0400 Received: from mail.kernel.org ([198.145.29.99]:54608 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726298AbgDXJZt (ORCPT ); Fri, 24 Apr 2020 05:25:49 -0400 Received: from pali.im (pali.im [31.31.79.79]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mail.kernel.org (Postfix) with ESMTPSA id B200D20724; Fri, 24 Apr 2020 09:25:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587720348; bh=t7xTZ9J4en/MjkiMHZhzp48oDSHJbtjCC8DX8NgHS6k=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=X4YgCg8G/j90ojHlYaCmhVdLvy25pkyqmH/enHwEAuRNnICzXcXsRWhSuZAlrrfZB u3VEuVXG3U2gImJ6i671jlC7l+AiWade3PHeqQozSDdgkkrTBZU3DQhCbAswCSW0b/ EWifhAaDjPP22grjvC7Q0MuGBtNbC87MtW1O9ZlY= Received: by pali.im (Postfix) id 5B27C82E; Fri, 24 Apr 2020 11:25:46 +0200 (CEST) Date: Fri, 24 Apr 2020 11:25:46 +0200 From: Pali =?utf-8?B?Um9ow6Fy?= To: Bjorn Helgaas Cc: linux-pci@vger.kernel.org, Jason Cooper , Andrew Lunn , Gregory Clement , Sebastian Hesselbarth , Thomas Petazzoni , Lorenzo Pieralisi , Andrew Murray , Bjorn Helgaas , Remi Pommarel , Tomasz Maciej Nowak , Xogium , Marek =?utf-8?B?QmVow7pu?= Subject: Re: [PATCH v2 4/9] PCI: aardvark: issue PERST via GPIO Message-ID: <20200424092546.25p3hdtkehohe3xw@pali> References: <20200421111701.17088-1-marek.behun@nic.cz> <20200421111701.17088-5-marek.behun@nic.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20200421111701.17088-5-marek.behun@nic.cz> User-Agent: NeoMutt/20180716 Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Tuesday 21 April 2020 13:16:56 Marek Behún wrote: > From: Pali Rohár > > Add support for issuing PERST via GPIO specified in 'reset-gpios' > property (as described in PCI device tree bindings). > > Some buggy cards (e.g. Compex WLE900VX or WLE1216) are not detected > after reboot when PERST is not issued during driver initialization. > > Tested on Turris MOX. > > Signed-off-by: Pali Rohár > --- > drivers/pci/controller/pci-aardvark.c | 32 +++++++++++++++++++++++++++ > 1 file changed, 32 insertions(+) > > diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c > index 606bae1e7a88..e2d18094d8ca 100644 > --- a/drivers/pci/controller/pci-aardvark.c > +++ b/drivers/pci/controller/pci-aardvark.c ... > +static void advk_pcie_issue_perst(struct advk_pcie *pcie) > +{ > + if (!pcie->reset_gpio) > + return; > + > + dev_info(&pcie->pdev->dev, "issuing PERST via reset GPIO for 1ms\n"); > + gpiod_set_value_cansleep(pcie->reset_gpio, 1); > + usleep_range(1000, 2000); > + gpiod_set_value_cansleep(pcie->reset_gpio, 0); > +} After more testing we will have to increase this timeout to 10ms as some Compex cards are sometimes not detected with current 1ms timeout. I will do it in V3 patch series. Bjorn, do you know if there is a defined timeout in PCIE specification how long should be card in PERST? I looked into others pci kernel drivers and basically every driver is using its own timeout. pcie-kirin.c --> usleep_range(20000, 25000); pcie-qcom.c --> usleep_range(1000, 1000 + 500); msleep(100); pci-mvebu.c --> udelay(100); pci-tegra.c --> usleep_range(1000, 2000); pcie-iproc.c --> udelay(250); pcie-mediatek.c --> no delay pci-imx6.c --> msleep(100); But I guess that this timeout should not depend on driver or pci controller, but rather on connected card or on some recommended value if defined by PCIE specification.