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 Received: from mail.kernel.org (mail.kernel.org [198.145.29.99]) by smtp.lore.kernel.org (Postfix) with ESMTP id 5308DC433F5 for ; Mon, 4 Oct 2021 08:53:40 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 1CAD9613A2 for ; Mon, 4 Oct 2021 08:53:40 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229716AbhJDIz1 (ORCPT ); Mon, 4 Oct 2021 04:55:27 -0400 Received: from foss.arm.com ([217.140.110.172]:51188 "EHLO foss.arm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229631AbhJDIz1 (ORCPT ); Mon, 4 Oct 2021 04:55:27 -0400 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 78D47101E; Mon, 4 Oct 2021 01:53:38 -0700 (PDT) Received: from lpieralisi (e121166-lin.cambridge.arm.com [10.1.196.255]) by usa-sjc-imap-foss1.foss.arm.com (Postfix) with ESMTPSA id 8D47B3F66F; Mon, 4 Oct 2021 01:53:37 -0700 (PDT) Date: Mon, 4 Oct 2021 09:53:35 +0100 From: Lorenzo Pieralisi To: Marek =?iso-8859-1?Q?Beh=FAn?= Cc: Bjorn Helgaas , Thomas Petazzoni , Bjorn Helgaas , linux-pci@vger.kernel.org, pali@kernel.org Subject: Re: [PATCH 09/13] PCI: aardvark: Implement re-issuing config requests on CRS response Message-ID: <20211004085335.GC22336@lpieralisi> References: <20211001195856.10081-10-kabel@kernel.org> <20211002163519.GA973164@bhelgaas> <20211004092148.6e18f6f5@thinkpad> MIME-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1 Content-Disposition: inline Content-Transfer-Encoding: 8bit In-Reply-To: <20211004092148.6e18f6f5@thinkpad> User-Agent: Mutt/1.9.4 (2018-02-28) Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Mon, Oct 04, 2021 at 09:21:48AM +0200, Marek Behún wrote: > On Sat, 2 Oct 2021 11:35:19 -0500 > Bjorn Helgaas wrote: > > > On Fri, Oct 01, 2021 at 09:58:52PM +0200, Marek Behún wrote: > > > From: Pali Rohár > > > > > > Commit 43f5c77bcbd2 ("PCI: aardvark: Fix reporting CRS value") fixed > > > handling of CRS response and when CRSSVE flag was not enabled it marked CRS > > > response as failed transaction (due to simplicity). > > > > > > But pci-aardvark.c driver is already waiting up to the PIO_RETRY_CNT count > > > for PIO config response and so we can with a small change implement > > > re-issuing of config requests as described in PCIe base specification. > > > > > > This change implements re-issuing of config requests when response is CRS. > > > Set upper bound of wait cycles to around PIO_RETRY_CNT, afterwards the > > > transaction is marked as failed and an all-ones value is returned as > > > before. > > > > Does this fix a problem? > > Hello Bjorn, > > Pali has suspisions that certain Marvell WiFi cards may need this [1] > to work, but we do not have them so we cannot test this. > > I guess you think this should be considered a new feature instead of a > fix, so that the Fixes tag should be removed, yes? Pali was of the > opinion that this patch "fixes" the driver to conform more to the PCIe > specification, that is why we added the Fixes tag. > > Anyway if you think this should be considered a new feature, this patch > can be skipped. The following patches apply even without it. I do not think we should apply to the mainline a fix that can't be tested sorry, I will skip this patch. Thanks, Lorenzo > Marek > > [1] > https://lore.kernel.org/linux-wireless/CAHp75Vd5iCLELx8s+Zvcj8ufd2bN6CK26soDMkZyC1CwMO2Qeg@mail.gmail.com/