From mboxrd@z Thu Jan 1 00:00:00 1970 From: Murali Karicheri Subject: Re: Micrel Phy - Is there a way to configure the Phy not to do 802.3x flow control? Date: Thu, 10 Mar 2016 17:51:09 -0500 Message-ID: <56E1FA5D.9090003@ti.com> References: <56D8B83E.7000303@ti.com> <56D8D3D7.6070900@gmail.com> <56E1A55F.3090906@ti.com> <56E1B75F.9070100@gmail.com> <56E1CD4D.20405@ti.com> Mime-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit To: Florian Fainelli , , "open list:TI NETCP ETHERNET DRIVER" , "Kwok, WingMan" Return-path: Received: from devils.ext.ti.com ([198.47.26.153]:36517 "EHLO devils.ext.ti.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932089AbcCJWvJ (ORCPT ); Thu, 10 Mar 2016 17:51:09 -0500 In-Reply-To: <56E1CD4D.20405@ti.com> Sender: netdev-owner@vger.kernel.org List-ID: On 03/10/2016 02:38 PM, Murali Karicheri wrote: > On 03/10/2016 01:05 PM, Florian Fainelli wrote: >> On 10/03/16 08:48, Murali Karicheri wrote: >>> On 03/03/2016 07:16 PM, Florian Fainelli wrote: >>>> On 03/03/16 14:18, Murali Karicheri wrote: >>>>> Hi, >>>>> >>>>> We are using Micrel Phy in one of our board and wondering if we can force the >>>>> Phy to disable flow control at start. I have a 1G ethernet switch connected >>>>> to Phy and the phy always enable flow control. I would like to configure the >>>>> phy not to flow control. Is that possible and if yes, what should I do in the >>>>> my Ethernet driver to tell the Phy not to enable flow control? >>>> >>>> The PHY is not doing flow control per-se, your pseudo Ethernet MAC in >>>> the switch is doing, along with the link partner advertising support for >>>> it. You would want to make sure that your PHY device interface (provided >>>> that you are using the PHY library) is not starting with Pause >>>> advertised, but it could be supported. >>> >>> Understood that Phy is just advertise FC. The Micrel phy for 9031 advertise >>> by default FC supported. After negotiation, I see that Phylib provide the >>> link status with parameter pause = 1, asym_pause = 1. How do I tell the Phy not >>> to advertise? >>> >>> I call following sequence in the Ethernet driver. >>> >>> of_phy_connect(x,y,hndlr,a,z); >> >> Here you should be able to change phydev->advertising and >> phydev->supported to mask the ADVERTISED_Pause | ADVERTISED_AsymPause >> bits and have phy_start() restart with that which should disable pause >> and asym_pause as seen by your adjust_link handler. >> > Ok. Good point. I will try this. Thanks for your suggestion. > I made following changes. The phylib still report flow control enabled to the driver. Some bug in the phylib/phydev? + + printk("slave->phy->supported %x, slave->phy->advertising %x\n", + slave->phy->supported, slave->phy->advertising); + slave->phy->supported &= + ~(SUPPORTED_Pause | SUPPORTED_Asym_Pause); + slave->phy->advertising = slave->phy->supported; + printk("slave->phy->supported %x, slave->phy->advertising %x\n", + slave->phy->supported, slave->phy->advertising); phy_start(slave->phy); + printk("slave->phy->supported %x, slave->phy->advertising %x\n", + slave->phy->supported, slave->phy->advertising); phy_read_status(slave->phy); [ 10.757001] slave->phy->supported 22ff, slave->phy->advertising 22ff [ 10.763354] slave->phy->supported 2ff, slave->phy->advertising 2ff [ 10.769552] slave->phy->supported 2ff, slave->phy->advertising 2ff [ 10.776045] netcp-1.0 2620110.netcp eth0: Link is Down udhcpc (v1.23.1) started Sending discover... Sending discover... [ 14.757280] netcp-1.0 2620110.netcp eth0: Link is Up - 1Gbps/Full - flow control rx/tx Sending discover... Sending select for 158.218.103.170... Lease of 158.218.103.170 obtained, lease time 28800 /etc/udhcpc.d/50default: Adding DNS 192.0.2.2 /etc/udhcpc.d/50default: Adding DNS 192.0.2.3 > Murali >>> phy_start() >>> >>> Now in hndlr() I have pause = 1, asym_pause = 1, in phy_device ptr. How can >>> I tell the phy not to advertise initially? > > -- Murali Karicheri Linux Kernel, Keystone