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=-2.3 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,MAILING_LIST_MULTI,SPF_PASS,USER_AGENT_MUTT autolearn=ham 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 E14ACC282CE for ; Fri, 5 Apr 2019 20:27:34 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [209.132.180.67]) by mail.kernel.org (Postfix) with ESMTP id B08402146F for ; Fri, 5 Apr 2019 20:27:34 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (1024-bit key) header.d=lunn.ch header.i=@lunn.ch header.b="WIsc88Ra" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1726475AbfDEU1d (ORCPT ); Fri, 5 Apr 2019 16:27:33 -0400 Received: from vps0.lunn.ch ([185.16.172.187]:51942 "EHLO vps0.lunn.ch" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1725973AbfDEU1d (ORCPT ); Fri, 5 Apr 2019 16:27:33 -0400 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=lunn.ch; s=20171124; h=In-Reply-To:Content-Type:MIME-Version:References:Message-ID: Subject:Cc:To:From:Date:Sender:Reply-To:Content-Transfer-Encoding:Content-ID: Content-Description:Resent-Date:Resent-From:Resent-Sender:Resent-To:Resent-Cc :Resent-Message-ID:List-Id:List-Help:List-Unsubscribe:List-Subscribe: List-Post:List-Owner:List-Archive; bh=iaD/l7UUuxMYmoAXaLrYtnGoSilCqWfI4CbQwz7s/Xc=; b=WIsc88RayCay7P2H8tIJY5Z5dM KnsHn6HF4GKKmYc4oh3q+/a0xm5fIxVTAAr6HqMH2umvXWX8nUbUUiB92fDWbH5/uGdww2XMYQCOx RmQ9qDPpR52WHkR4kJDU2q3XZWj/OOdnHnvUF2UNfGS2Fb9rJlXhFo0KCAvg5xhOIt0Y=; Received: from andrew by vps0.lunn.ch with local (Exim 4.89) (envelope-from ) id 1hCVQv-0006jJ-QV; Fri, 05 Apr 2019 22:27:29 +0200 Date: Fri, 5 Apr 2019 22:27:29 +0200 From: Andrew Lunn To: Heiner Kallweit Cc: Florian Fainelli , David Miller , "netdev@vger.kernel.org" Subject: Re: [PATCH net-next] net: phy: improve link partner capability detection Message-ID: <20190405202729.GK23536@lunn.ch> References: <20190405194821.GI23536@lunn.ch> <6a86f31f-dda8-77d9-aace-9ad1ad770a28@gmail.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <6a86f31f-dda8-77d9-aace-9ad1ad770a28@gmail.com> User-Agent: Mutt/1.5.23 (2014-03-12) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Fri, Apr 05, 2019 at 10:04:22PM +0200, Heiner Kallweit wrote: > On 05.04.2019 21:48, Andrew Lunn wrote: > > On Fri, Apr 05, 2019 at 09:23:13PM +0200, Heiner Kallweit wrote: > >> genphy_read_status() so far checks phydev->supported, not the actual > >> PHY capabilities. This can make a difference if the supported speeds > >> have been limited by of_set_phy_supported() or phy_set_max_speed(). > >> > >> It seems that this issue only affects the link partner advertisements > >> as displayed by ethtool. Also this patch wouldn't apply to older > >> kernels because linkmode bitmaps have been introduced recently. > >> Therefore net-next. > > > > Hi Heiner > > > Hi Andrew, > > > Are you saying, if the local PHY/MAC does not support 1000Base-T, we > > should not check if the peer is advertising 1000Base-T? That seems > > wrong. We should report everything it offers. The fact we cannot make > > use of 1000Base-T should not matter, and resolving of the auto-get > > should do the right thing when presented with modes it cannot use. > > > Link partner gigabit advertisement is reported in register MII_STAT1000. > If we have a 100MBit PHY w/o this register, then we will never know > whether the link partner supports gigabit. Hi Heiner There seems to be two uses cases: A Fast MAC connected to a Fast PHY. In that case, MII_STAT1000 probably does not exist, so we should not read it. Hopefully .features says BASIC, or if we ask the PHY what is it, it reports it is a Fast PHY. A Fast MAC connected to a Giga PHY. The MAC driver will of used phy_set_max_speed() to indicate its limits. In that case, MII_STAT1000 does exist and we should report what the peer is advertising. Andrew