From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from bmailout1.hostsharing.net (bmailout1.hostsharing.net [83.223.95.100]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id 1484D155743 for ; Thu, 19 Dec 2024 07:41:37 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=83.223.95.100 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734594102; cv=none; b=Vkohia521BLOg7QMtpxACRvmfJ4CrLoWERo7OziVjDJ0UGdtgCImllyPH2zIra5+SwKVAdFY34erAypGGG3YPMJSkHTTTV5RpwoY1YT0nkdQDT2GlECb7PmsBtxXBbWEbJvPSxG/IuqEUgM+6Bae7iLFMakHLz1jI+0Srhm1kFM= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1734594102; c=relaxed/simple; bh=sNYVbAHYpK8sbV26B54xzaBv4AWz0B4HYf2+x+aHhNY=; h=Date:From:To:Cc:Subject:Message-ID:References:MIME-Version: Content-Type:Content-Disposition:In-Reply-To; b=FlQ/BqGi1vevlauBBdkGEou4c5LniKClkW4mQalKf4bkpy4ZoxAD/BDleW5bxub0jtp6FZ1B96e7Cgx6V4Y4TbUq93q1m4YvabmC5Ad437WHJvITUTVj2nfU3eCvH4MDD0RTefE+0AM4l6l3+15QwzM7ISzU6AazHs6laodnpVM= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=wunner.de; spf=none smtp.mailfrom=h08.hostsharing.net; arc=none smtp.client-ip=83.223.95.100 Authentication-Results: smtp.subspace.kernel.org; dmarc=none (p=none dis=none) header.from=wunner.de Authentication-Results: smtp.subspace.kernel.org; spf=none smtp.mailfrom=h08.hostsharing.net Received: from h08.hostsharing.net (h08.hostsharing.net [83.223.95.28]) (using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits) key-exchange X25519 server-signature RSA-PSS (4096 bits) server-digest SHA256 client-signature RSA-PSS (4096 bits) client-digest SHA256) (Client CN "*.hostsharing.net", Issuer "RapidSSL TLS RSA CA G1" (verified OK)) by bmailout1.hostsharing.net (Postfix) with ESMTPS id 55E27300011A6; Thu, 19 Dec 2024 08:41:30 +0100 (CET) Received: by h08.hostsharing.net (Postfix, from userid 100393) id 4325E2BC2F9; Thu, 19 Dec 2024 08:41:30 +0100 (CET) Date: Thu, 19 Dec 2024 08:41:30 +0100 From: Lukas Wunner To: Krzysztof Wilczy??ski Cc: Ilpo =?iso-8859-1?Q?J=E4rvinen?= , Bjorn Helgaas , linux-pci@vger.kernel.org, Niklas Schnelle , Jonathan Cameron , Mika Westerberg , "Maciej W. Rozycki" , Mario Limonciello Subject: Re: [PATCH for-linus v3 1/2] PCI: Honor Max Link Speed when determining supported speeds Message-ID: References: <7bbd48eb-efaf-260f-ad8d-9fe7f2209812@linux.intel.com> <20241218234357.GA1444967@rocinante> Precedence: bulk X-Mailing-List: linux-pci@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20241218234357.GA1444967@rocinante> On Thu, Dec 19, 2024 at 08:43:57AM +0900, Krzysztof Wilczy??ski wrote: > > > The GENMASK() macro used herein specifies 0 as lowest bit, even though > > > the Supported Link Speeds Vector ends at bit 1. This is done on purpose > > > to avoid a GENMASK(0, 1) macro if Max Link Speed is zero. That macro > > > would be invalid as the lowest bit is greater than the highest bit. > > > Ilpo has witnessed a zero Max Link Speed on Root Complex Integrated > > > Endpoints in particular, so it does occur in practice. > > > > Thanks for adding this extra information. > > > > I'd also add reference to r6.2 section 7.5.3 which states those registers > > are required for RPs, Switch Ports, Bridges, and Endpoints _that are not > > RCiEPs_. My reading is that implies they're not required from RCiEPs. > > Let me know how you would like to update the commit message. I will do it > directly on the branch. FWIW, I edited the commit message like this on my local branch: -Endpoints in particular, so it does occur in practice. +Endpoints in particular, so it does occur in practice. (The Link +Capabilities Register is optional on RCiEPs per PCIe r6.2 sec 7.5.3.) In other words, I just added the sentence in parentheses. But maybe Ilpo has another wording preference... :) Thanks, Lukas