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 778DFC433EF for ; Mon, 4 Oct 2021 10:19:44 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 59902613A4 for ; Mon, 4 Oct 2021 10:19:44 +0000 (UTC) Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S229945AbhJDKVc (ORCPT ); Mon, 4 Oct 2021 06:21:32 -0400 Received: from mail.kernel.org ([198.145.29.99]:38856 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S229478AbhJDKVb (ORCPT ); Mon, 4 Oct 2021 06:21:31 -0400 Received: by mail.kernel.org (Postfix) with ESMTPSA id 6E575613A2; Mon, 4 Oct 2021 10:19:41 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1633342782; bh=AxMsJc0OWSGhY/JRXJnGZ7RDrxofSUQSVhY6tCgGoag=; h=Date:From:To:Cc:Subject:In-Reply-To:References:From; b=fqvn1Oph8sNvlKhUwdbBrx4vWhiXNlseR1WTO04xNGNgeFjscwTWdHbCvg4haGt7v 6zLXuWEfdeDwN9HCKHqdwNU4/DSLYQYNHvMD2ek5uUxpqgMuAaFxTqWlqXpPg++6ul xrBG/b4Smr07R/tvhqviTKWXnckOJFJQOMpT9tO+Zj4HM7iFFOvPEyXLxXUNs8GOnq wzjzm86ydvGIjvGK0ZIqClVfci4akZS+5GnLaMZI3eMKjjqx6gA3grO9MLn3nq4z+H v+JsJRKog6GH43DhWhXhcm+cMhN0rbKS9MJsnN57/YJXfW+BzMyulUydFV0hp34Sdk vIEHnEm/GfX3A== Date: Mon, 4 Oct 2021 12:19:38 +0200 From: Marek =?UTF-8?B?QmVow7pu?= To: Lorenzo Pieralisi 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: <20211004121938.546d8f73@thinkpad> In-Reply-To: <20211004085335.GC22336@lpieralisi> References: <20211001195856.10081-10-kabel@kernel.org> <20211002163519.GA973164@bhelgaas> <20211004092148.6e18f6f5@thinkpad> <20211004085335.GC22336@lpieralisi> X-Mailer: Claws Mail 3.18.0 (GTK+ 2.24.33; x86_64-pc-linux-gnu) MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: quoted-printable Precedence: bulk List-ID: X-Mailing-List: linux-pci@vger.kernel.org On Mon, 4 Oct 2021 09:53:35 +0100 Lorenzo Pieralisi wrote: > On Mon, Oct 04, 2021 at 09:21:48AM +0200, Marek Beh=C3=BAn wrote: > > On Sat, 2 Oct 2021 11:35:19 -0500 > > Bjorn Helgaas wrote: > > =20 > > > On Fri, Oct 01, 2021 at 09:58:52PM +0200, Marek Beh=C3=BAn wrote: =20 > > > > From: Pali Roh=C3=A1r > > > >=20 > > > > Commit 43f5c77bcbd2 ("PCI: aardvark: Fix reporting CRS value") fixed > > > > handling of CRS response and when CRSSVE flag was not enabled it ma= rked CRS > > > > response as failed transaction (due to simplicity). > > > >=20 > > > > But pci-aardvark.c driver is already waiting up to the PIO_RETRY_CN= T count > > > > for PIO config response and so we can with a small change implement > > > > re-issuing of config requests as described in PCIe base specificati= on. > > > >=20 > > > > 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. =20 > > >=20 > > > Does this fix a problem? =20 > >=20 > > Hello Bjorn, > >=20 > > 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. > >=20 > > 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. > >=20 > > Anyway if you think this should be considered a new feature, this patch > > can be skipped. The following patches apply even without it. =20 >=20 > I do not think we should apply to the mainline a fix that can't be > tested sorry, I will skip this patch. Lorenzo, my explanation was incorrect. The functionality added by this patch _is_ tested and correctly does a retry: it was done by simulating a CRS reply. We just don't know whether there are real cards used by users that need this functionality (the mentioned Marvell card may be such a card). Marek