From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Hutchings Subject: Re: [PATCH 2.6.38.4] mii: add support of pause frames in mii_get_an Date: Thu, 28 Apr 2011 13:45:38 +0100 Message-ID: <1303994738.3032.455.camel@localhost> References: <1303962554.15395.1.camel@artpol-thinkpad> <20110427214902.0826a4d1@nehalam> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 7bit Cc: artpol , linux-kernel@vger.kernel.org, davem@davemloft.net, netdev@vger.kernel.org To: Stephen Hemminger Return-path: In-Reply-To: <20110427214902.0826a4d1@nehalam> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org On Wed, 2011-04-27 at 21:49 -0700, Stephen Hemminger wrote: > On Thu, 28 Apr 2011 10:49:14 +0700 > artpol wrote: > > > Add support of pause frames advertise in mii_get_an. This provides all drivers > > that use mii_ethtool_gset to represent their own and Link partner flow control > > abilities in ethtool. > > > > Signed-off-by: Artem Polyakov > > > > --- > > > > --- linux-2.6.38.4/drivers/net/mii.c.orig 2011-04-28 08:46:13.000000000 +0700 > > +++ linux-2.6.38.4/drivers/net/mii.c 2011-04-25 23:04:20.694981968 +0700 > > @@ -49,6 +49,10 @@ static u32 mii_get_an(struct mii_if_info > > result |= ADVERTISED_100baseT_Half; > > if (advert & ADVERTISE_100FULL) > > result |= ADVERTISED_100baseT_Full; > > + if (advert & ADVERTISE_PAUSE_CAP) > > + result |= ADVERTISED_Pause; > > + if (advert & ADVERTISE_PAUSE_ASYM) > > + result |= ADVERTISED_Asym_Pause; > > > > return result; > > } > > One common driver problem is that auto negotiation of pause > is really a separate operation from negotiation of speed. > It should be possible to force no flow-control but still negotiate > speed and vice-versa. If you want to force flow control then turn off pause autoneg. If you want to force speed then turn off advertising of other speeds. > The ethtool api breaks this into two operations > but many drivers munge them together. There is some interaction between set_pauseparam and set_settings if pause autoneg is enabled, which is why we have the mii_advertise_flowctrl() function. Anyway, this patch covers reporting only. Ben. -- Ben Hutchings, Senior Software Engineer, Solarflare Not speaking for my employer; that's the marketing department's job. They asked us to note that Solarflare product names are trademarked.