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=-8.1 required=3.0 tests=DKIM_INVALID,DKIM_SIGNED, HEADER_FROM_DIFFERENT_DOMAINS,INCLUDES_PATCH,MAILING_LIST_MULTI,SIGNED_OFF_BY, SPF_HELO_NONE,SPF_PASS,URIBL_BLOCKED,USER_AGENT_SANE_1 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 95B06C433DF for ; Tue, 26 May 2020 16:34:08 +0000 (UTC) Received: from vger.kernel.org (vger.kernel.org [23.128.96.18]) by mail.kernel.org (Postfix) with ESMTP id 6BB982073B for ; Tue, 26 May 2020 16:34:08 +0000 (UTC) Authentication-Results: mail.kernel.org; dkim=fail reason="signature verification failed" (2048-bit key) header.d=armlinux.org.uk header.i=@armlinux.org.uk header.b="O196D2c7" Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1729044AbgEZQdl (ORCPT ); Tue, 26 May 2020 12:33:41 -0400 Received: from lindbergh.monkeyblade.net ([23.128.96.19]:37788 "EHLO lindbergh.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1728339AbgEZQdk (ORCPT ); Tue, 26 May 2020 12:33:40 -0400 Received: from pandora.armlinux.org.uk (pandora.armlinux.org.uk [IPv6:2001:4d48:ad52:3201:214:fdff:fe10:1be6]) by lindbergh.monkeyblade.net (Postfix) with ESMTPS id 03098C03E96D for ; Tue, 26 May 2020 09:33:40 -0700 (PDT) DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=armlinux.org.uk; s=pandora-2019; h=Sender:In-Reply-To:Content-Type: MIME-Version:References:Message-ID:Subject:Cc:To:From:Date: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=qVkBQgAFIZOykC7HbI4BSicA+egFu//ByWvBBkbTvGA=; b=O196D2c7iR2HIK02rwpDeyPnM DZ9NxTrQIrQPgfDAxsUhM/4iVnz85KD87ORko0O6WAaD9eOnaZdGcYj59Wbmx/9CFFsnjGZYgcFCS VWHi0Yt3fRDBGGcE0nTBH6yN4s0k0BDIHgQVOMzJzL2BGJwRmqGWz6VHYrs0Dvq3LOwqavHUIPbdf w+cuSIJRhoHb2OiIzq1Ioj8QaQgWalMWUECt75VDHzMESNY0Ga9E6wLouJ+9MzEtWZMm6m25v85P6 D98ZJEL9JS9K0z/tRjdW3d16Z22BPtZuzdj35PrGAL0HsFE8cXYRy2L004wpdNbjcAuUONSlCnIPa wcdW/S7YA==; Received: from shell.armlinux.org.uk ([2002:4e20:1eda:1:5054:ff:fe00:4ec]:34858) by pandora.armlinux.org.uk with esmtpsa (TLSv1.2:ECDHE-RSA-AES256-GCM-SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jdcWB-0008KJ-Sh; Tue, 26 May 2020 17:33:32 +0100 Received: from linux by shell.armlinux.org.uk with local (Exim 4.92) (envelope-from ) id 1jdcW9-0005XK-Tb; Tue, 26 May 2020 17:33:29 +0100 Date: Tue, 26 May 2020 17:33:29 +0100 From: Russell King - ARM Linux admin To: Jeremy Linton Cc: Andrew Lunn , Heiner Kallweit , Florian Fainelli , netdev@vger.kernel.org Subject: Re: [PATCH RFC 5/7] net: phy: set devices_in_package only after validation Message-ID: <20200526163329.GE1605@shell.armlinux.org.uk> References: <20200526142948.GY1551@shell.armlinux.org.uk> <758bd1ef-e7f8-f746-af76-b54c14dd5af2@arm.com> <20200526155028.GF1551@shell.armlinux.org.uk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20200526155028.GF1551@shell.armlinux.org.uk> User-Agent: Mutt/1.10.1 (2018-07-13) Sender: netdev-owner@vger.kernel.org Precedence: bulk List-ID: X-Mailing-List: netdev@vger.kernel.org On Tue, May 26, 2020 at 04:50:28PM +0100, Russell King - ARM Linux admin wrote: > On Tue, May 26, 2020 at 10:39:49AM -0500, Jeremy Linton wrote: > > Hi, > > > > On 5/26/20 9:31 AM, Russell King wrote: > > > Only set the devices_in_package to a non-zero value if we find a valid > > > value for this field, so we avoid leaving it set to e.g. 0x1fffffff. > > > > > > Signed-off-by: Russell King > > > --- > > > drivers/net/phy/phy_device.c | 17 ++++++++++------- > > > 1 file changed, 10 insertions(+), 7 deletions(-) > > > > > > diff --git a/drivers/net/phy/phy_device.c b/drivers/net/phy/phy_device.c > > > index fa9164ac0f3d..a483d79cfc87 100644 > > > --- a/drivers/net/phy/phy_device.c > > > +++ b/drivers/net/phy/phy_device.c > > > @@ -730,13 +730,13 @@ static int get_phy_c45_ids(struct mii_bus *bus, int addr, u32 *phy_id, > > > struct phy_c45_device_ids *c45_ids) > > > { > > > const int num_ids = ARRAY_SIZE(c45_ids->device_ids); > > > - u32 *devs = &c45_ids->devices_in_package; > > > + u32 devs_in_pkg = 0; > > > int i, ret, phy_reg; > > > /* Find first non-zero Devices In package. Device zero is reserved > > > * for 802.3 c45 complied PHYs, so don't probe it at first. > > > */ > > > - for (i = 1; i < MDIO_MMD_NUM && *devs == 0; i++) { > > > + for (i = 1; i < MDIO_MMD_NUM && devs_in_pkg == 0; i++) { > > > if (i >= 8) { > > > /* Only probe for the devices-in-package if there > > > * is a PHY reporting as present here; this avoids > > > @@ -750,22 +750,22 @@ static int get_phy_c45_ids(struct mii_bus *bus, int addr, u32 *phy_id, > > > if (!ret) > > > continue; > > > } > > > - phy_reg = get_phy_c45_devs_in_pkg(bus, addr, i, devs); > > > + phy_reg = get_phy_c45_devs_in_pkg(bus, addr, i, &devs_in_pkg); > > > if (phy_reg < 0) > > > return -EIO; > > > } > > > - if ((*devs & 0x1fffffff) == 0x1fffffff) { > > > + if ((devs_in_pkg & 0x1fffffff) == 0x1fffffff) { > > > /* If mostly Fs, there is no device there, then let's probe > > > * MMD 0, as some 10G PHYs have zero Devices In package, > > > * e.g. Cortina CS4315/CS4340 PHY. > > > */ > > > - phy_reg = get_phy_c45_devs_in_pkg(bus, addr, 0, devs); > > > + phy_reg = get_phy_c45_devs_in_pkg(bus, addr, 0, &devs_in_pkg); > > > if (phy_reg < 0) > > > return -EIO; > > > /* no device there, let's get out of here */ > > > - if ((*devs & 0x1fffffff) == 0x1fffffff) { > > > + if ((devs_in_pkg & 0x1fffffff) == 0x1fffffff) { > > > *phy_id = 0xffffffff; > > > return 0; > > > } > > > @@ -773,7 +773,7 @@ static int get_phy_c45_ids(struct mii_bus *bus, int addr, u32 *phy_id, > > > /* Now probe Device Identifiers for each device present. */ > > > for (i = 1; i < num_ids; i++) { > > > - if (!(c45_ids->devices_in_package & (1 << i))) > > > + if (!(devs_in_pkg & (1 << i))) > > > continue; > > > phy_reg = mdiobus_c45_read(bus, addr, i, MII_PHYSID1); > > > @@ -786,6 +786,9 @@ static int get_phy_c45_ids(struct mii_bus *bus, int addr, u32 *phy_id, > > > return -EIO; > > > c45_ids->device_ids[i] |= phy_reg; > > > } > > > + > > > + c45_ids->devices_in_package = devs_in_pkg; > > > + > > > *phy_id = 0; > > > return 0; > > > } > > > > > > > You have solved the case of 0xFFFFFFFFF devices in package, but It looks > > like the case of devs in package = 0 still gets a successful return from > > this path. Which can still create phys with phy_id=0 and 0 MMDs AFAIK. > > Correct - I'm not looking to change the behaviour in this patch > beyond the intended change of ensuring that c45_ids->devices_in_package > remains untouched until we intend to return successfully. > > The zero MMDs issue is an entirely orthogonal problem not addressed > in this series. Please note that this problem has existed back to the original addition of clause 45 support in this commit: commit ac28b9f8cd66d6bc54f8063df59e99abd62173a4 Author: David Daney Date: Wed Jun 27 07:33:35 2012 +0000 I think it only becomes a problem when we start autoprobing clause 45 PHYs. The scanning in __mdiobus_register() does not support locating a clause 45 PHY - it only issues clause 22 cycles. If you are lucky enough to have a clause 45 PHY that responds to clause 22 cycles, then the PHY device will be created using the information in the clause 22 registers. get_phy_device() is called with is_c45 false. Hence, the path above will not be used. The only way for a clause 45 PHY to be created is explicitly via some method - either through DT declaring a C45 PHY, or via a driver calling get_phy_device() with is_c45 true. There are two ethernet drivers which do this in drivers/net, using explicit addresses rather than autoprobing. -- RMK's Patch system: https://www.armlinux.org.uk/developer/patches/ FTTC for 0.8m (est. 1762m) line in suburbia: sync at 13.1Mbps down 424kbps up