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=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI, SIGNED_OFF_BY,SPF_PASS,URIBL_BLOCKED,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 B19A7C10F03 for ; Tue, 23 Apr 2019 22:20:38 +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 7DEE7217D9 for ; Tue, 23 Apr 2019 22:20:38 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=pass (2048-bit key) header.d=lists.infradead.org header.i=@lists.infradead.org header.b="A6qJRaHQ" DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 7DEE7217D9 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=triplefau.lt 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=+YZnHZgt9hVxzGinDLvZTPq/hGyRCLZXQM4jDWqTEeU=; b=A6qJRaHQnO8xSq GJGdl9ypKzwgN1f9jgTw3P6ZdRVe3NrpJ1+ZEFUtk+sII8WG/f3izdadQ8DAdR/foitKijRknrQ67 0q3KqcBz4NsG3PUitWGppdzwrV3t26WUC6/1GrAY2Ta7LdDhzmf50Il81DgXZVv2uoUJGRdYHuoLk aRosxiiBDN0R4S3u35wZt/2e5a/ygmvRs/BfGCTkjDszSRyqxjYHOpb5U4REDYn7SI3FOi6/nBGVt XScuDMUyExo5OXEGsNlgoSsNi23lpSOB4c/HEMv6ZO9FhYH1hIPr4aME0XxBBnDIRRqOiFfGld6Zs NGsVJdJ+UbPCaWJLLSfw==; Received: from localhost ([127.0.0.1] helo=bombadil.infradead.org) by bombadil.infradead.org with esmtp (Exim 4.90_1 #2 (Red Hat Linux)) id 1hJ3mB-0002jg-GJ; Tue, 23 Apr 2019 22:20:31 +0000 Received: from relay10.mail.gandi.net ([217.70.178.230]) by bombadil.infradead.org with esmtps (Exim 4.90_1 #2 (Red Hat Linux)) id 1hJ3m8-0002im-Ci for linux-arm-kernel@lists.infradead.org; Tue, 23 Apr 2019 22:20:29 +0000 Received: from localhost (unknown [88.190.179.123]) (Authenticated sender: repk@triplefau.lt) by relay10.mail.gandi.net (Postfix) with ESMTPSA id 7133724000A; Tue, 23 Apr 2019 22:20:18 +0000 (UTC) Date: Wed, 24 Apr 2019 00:29:18 +0200 From: Remi Pommarel To: Lorenzo Pieralisi Subject: Re: [PATCH] pci: aardvark: Wait for endpoint to be ready before training link Message-ID: <20190423222917.GN2754@voidbox.localdomain> References: <20190313213752.1246-1-repk@triplefau.lt> <20190423163215.GB26523@red-moon> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20190423163215.GB26523@red-moon> User-Agent: Mutt/1.10.1 (2018-07-13) X-CRM114-Version: 20100106-BlameMichelson ( TRE 0.8.0 (BSD) ) MR-646709E3 X-CRM114-CacheID: sfid-20190423_152028_584833_DC5E8E65 X-CRM114-Status: GOOD ( 18.29 ) X-BeenThere: linux-arm-kernel@lists.infradead.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: linux-pci@vger.kernel.org, linux-kernel@vger.kernel.org, Thomas Petazzoni , Miquel Raynal , Bjorn Helgaas , 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 Hi, On Tue, Apr 23, 2019 at 05:32:15PM +0100, Lorenzo Pieralisi wrote: > On Wed, Mar 13, 2019 at 10:37:52PM +0100, Remi Pommarel wrote: > > When configuring pcie reset pin from gpio (e.g. initially set by > > u-boot) to pcie function this pin goes low for a brief moment > > asserting the PERST# signal. Thus connected device enters fundamental > > reset process and link configuration can only begin after a minimal > > 100ms delay (see [1]). > > > > This makes sure that link is configured after at least 100ms from > > beginning of probe() callback (shortly after the reset pin function > > configuration switch through pinctrl subsytem). > > > > [1] "PCI Express Base Specification", REV. 2.1 > > PCI Express, March 4 2009, 6.6.1 Conventional Reset > > > > Signed-off-by: Remi Pommarel > > --- > > drivers/pci/controller/pci-aardvark.c | 17 ++++++++++++++--- > > 1 file changed, 14 insertions(+), 3 deletions(-) > > > > diff --git a/drivers/pci/controller/pci-aardvark.c b/drivers/pci/controller/pci-aardvark.c > > index a30ae7cf8e7e..70a1023d0ef1 100644 > > --- a/drivers/pci/controller/pci-aardvark.c > > +++ b/drivers/pci/controller/pci-aardvark.c > > @@ -177,6 +177,9 @@ > > > > #define PIO_TIMEOUT_MS 1 > > > > +/* Endpoint can take up to 100ms to be ready after a reset */ > > +#define ENDPOINT_RST_MS 100 > > + > > #define LINK_WAIT_MAX_RETRIES 10 > > #define LINK_WAIT_USLEEP_MIN 90000 > > #define LINK_WAIT_USLEEP_MAX 100000 > > @@ -242,8 +245,10 @@ static int advk_pcie_wait_for_link(struct advk_pcie *pcie) > > return -ETIMEDOUT; > > } > > > > -static void advk_pcie_setup_hw(struct advk_pcie *pcie) > > +static void > > +advk_pcie_setup_hw(struct advk_pcie *pcie, unsigned long ep_rdy_time) > > Nit: I prefer the prototype to be in one line, I wrap it for you. > > I am wondering why you need to pass in ep_rdy_time parameter when you > can easily compute it in the function itself. > The only reason for that is because the sooner I get the jiffies the lower the delay has to be. I was trying to reduce the impact of this delay to a minimum, but maybe the improvement is not worth it. -- Remi _______________________________________________ linux-arm-kernel mailing list linux-arm-kernel@lists.infradead.org http://lists.infradead.org/mailman/listinfo/linux-arm-kernel