From mboxrd@z Thu Jan 1 00:00:00 1970 From: Florian Fainelli Subject: Re: [PATCH] [v4] net: phy: phy drivers should not set SUPPORTED_[Asym_]Pause Date: Sun, 11 Dec 2016 11:45:15 -0800 Message-ID: <042cef25-4dca-d266-c5eb-4d2ed573f81a@gmail.com> References: <1481138451-28144-1-git-send-email-timur@codeaurora.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit To: Timur Tabi , David Miller , netdev@vger.kernel.org, jon.mason@broadcom.com, nks.gnu@gmail.com Return-path: Received: from mail-oi0-f67.google.com ([209.85.218.67]:36306 "EHLO mail-oi0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753620AbcLKTpS (ORCPT ); Sun, 11 Dec 2016 14:45:18 -0500 Received: by mail-oi0-f67.google.com with SMTP id u15so8574036oie.3 for ; Sun, 11 Dec 2016 11:45:18 -0800 (PST) In-Reply-To: <1481138451-28144-1-git-send-email-timur@codeaurora.org> Sender: netdev-owner@vger.kernel.org List-ID: Le 12/07/16 à 11:20, Timur Tabi a écrit : > Instead of having individual PHY drivers set the SUPPORTED_Pause and > SUPPORTED_Asym_Pause flags, phylib itself should set those flags, > unless there is a hardware erratum or other special case. During > autonegotiation, the PHYs will determine whether to enable pause > frame support. > > Pause frames are a feature that is supported by the MAC. It is the MAC > that generates the frames and that processes them. The PHY can only be > configured to allow them to pass through. > > This commit also effectively reverts the recently applied c7a61319 > ("net: phy: dp83848: Support ethernet pause frames"). > > So the new process is: > > 1) Unless the PHY driver overrides it, phylib sets the SUPPORTED_Pause > and SUPPORTED_AsymPause bits in phydev->supported. This indicates that > the PHY supports pause frames. > > 2) The MAC driver checks phydev->supported before it calls phy_start(). > If (SUPPORTED_Pause | SUPPORTED_AsymPause) is set, then the MAC driver > sets those bits in phydev->advertising, if it wants to enable pause > frame support. > > 3) When the link state changes, the MAC driver checks phydev->pause and > phydev->asym_pause, If the bits are set, then it enables the corresponding > features in the MAC. The algorithm is: > > if (phydev->pause) > The MAC should be programmed to receive and honor > pause frames it receives, i.e. enable receive flow control. > > if (phydev->pause != phydev->asym_pause) > The MAC should be programmed to transmit pause > frames when needed, i.e. enable transmit flow control. > > Signed-off-by: Timur Tabi This is already applied but: Reviewed-by: Florian Fainelli Thanks! -- Florian