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=-1.1 required=3.0 tests=DKIMWL_WL_HIGH,DKIM_SIGNED, DKIM_VALID,DKIM_VALID_AU,MAILING_LIST_MULTI,SPF_HELO_NONE,SPF_PASS autolearn=no 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 F2841C54FCB for ; Thu, 23 Apr 2020 22:17:17 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id C661D20784 for ; Thu, 23 Apr 2020 22:17:17 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587680237; bh=gAlXgZIt1VaY8pHL7oB8uzhzcKioRXzHTmt+jme0SJA=; h=Date:From:To:Cc:Subject:In-Reply-To:List-ID:From; b=l3gzdxfiEadFNxp+bHls5YElhl8leqj5rdo6Mf0hv15EKl+OIDGyt6D9QjWQKvcci aO3NtnANbMyMZfaNroTa8UEXl7P6da9Mwrh7qLZiPM3fiiJkhlIiyzYzF3z5rvGtzd uJrdia4tfyCl9HSHnmoIq2R8TS0lDtanp77k2OR0= Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726062AbgDWWRR (ORCPT ); Thu, 23 Apr 2020 18:17:17 -0400 Received: from mail.kernel.org ([198.145.29.99]:49762 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1726056AbgDWWRR (ORCPT ); Thu, 23 Apr 2020 18:17:17 -0400 Received: from localhost (mobile-166-175-187-210.mycingular.net [166.175.187.210]) (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 32FEC2074F; Thu, 23 Apr 2020 22:17:16 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=default; t=1587680236; bh=gAlXgZIt1VaY8pHL7oB8uzhzcKioRXzHTmt+jme0SJA=; h=Date:From:To:Cc:Subject:In-Reply-To:From; b=1PE4SoFy4SSurqGukoMHUBeHCiJBLdQ/e3iUMeNIDmbUc6QdCB9ouLbtSEMdHdLO0 LqaJKwh3M62ebF5VKYnOOi+tWeiF3bsdXV7E0Imp85/h72TQkzYLMhcy1v4VwGgEn9 qqMJL+iLwNz+h8HHlc48+Ogn99mmztGrG46/jVe4= Date: Thu, 23 Apr 2020 17:17:14 -0500 From: Bjorn Helgaas To: Pali =?iso-8859-1?Q?Roh=E1r?= Cc: Marek =?iso-8859-1?Q?Beh=FAn?= , linux-pci@vger.kernel.org, Jason Cooper , Andrew Lunn , Gregory Clement , Sebastian Hesselbarth , Thomas Petazzoni , Lorenzo Pieralisi , Andrew Murray , Remi Pommarel , Tomasz Maciej Nowak , Xogium , Rob Herring Subject: Re: [PATCH v2 4/9] PCI: aardvark: issue PERST via GPIO Message-ID: <20200423221714.GA247156@google.com> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20200423190202.ssbhwoupmssrdcyi@pali> Sender: linux-pci-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Thu, Apr 23, 2020 at 09:02:02PM +0200, Pali Rohár wrote: > On Thursday 23 April 2020 13:41:51 Bjorn Helgaas wrote: > > [+cc Rob] > > > > On Tue, Apr 21, 2020 at 01:16:56PM +0200, 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. > > > > Does this slot support hotplug? > > I have no idea. I have not heard that anybody tried hotplugging cards > with this aardvark pcie controller at runtime. > > This patch fixes initialization only at boot time when cards were > plugged prior powering board on. > > > If so, I don't think this fix will help the hot-add case, will it? > > I even do not know if aardvark HW supports it. And if yes, I think it is > unimplemented and/or broken. > > In documentation there is some interrupt register which could signal it, > but I it is not used by kernel's pci-aardvark.c driver. "lspci -vv" will show you whether the hardware claims to support it, e.g., 00:1c.0 PCI bridge: Intel Corporation Sunrise Point-LP PCI Express Root Port #1 Capabilities: [40] Express (v2) Root Port (Slot+), MSI 00 SltCap: AttnBtn- PwrCtrl- MRL- AttnInd- PwrInd- HotPlug- Surprise- If the right combination of bits are set there, pciehp will claim the port and support hotplug. Bjorn