From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH] Revert "net: mvneta: fix usage as a module on RGMII configurations" Date: Sun, 13 Apr 2014 23:14:57 -0400 (EDT) Message-ID: <20140413.231457.1275572148025135232.davem@davemloft.net> References: <1397380533-16012-1-git-send-email-thomas.petazzoni@free-electrons.com> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, ezequiel.garcia@free-electrons.com, gregory.clement@free-electrons.com, jason@lakedaemon.net, andrew@lunn.ch, sebastian.hesselbarth@gmail.com, alior@marvell.com, tawfik@marvell.com, linux-arm-kernel@lists.infradead.org, stable@vger.kernel.org To: thomas.petazzoni@free-electrons.com Return-path: In-Reply-To: <1397380533-16012-1-git-send-email-thomas.petazzoni@free-electrons.com> Sender: stable-owner@vger.kernel.org List-Id: netdev.vger.kernel.org From: Thomas Petazzoni Date: Sun, 13 Apr 2014 11:15:33 +0200 > This reverts commit e3a8786c10e75903f1269474e21fe8cb49c3a670. While > this commit allows to use the mvneta driver as a module on some > configurations, it breaks other configurations even if mvneta is used > built-in. > > This breakage is due to the fact that on some RGMII platforms, the PCS > bit has to be set, and on some other platforms, it has to be > cleared. At the moment, we lack informations to know exactly the > significance of this bit (the datasheet only says "enables PCS"), and > so we can't produce a patch that will work on all platforms at this > point. And since this change is breaking the network completely for > many users, it's much better to revert it for now. We'll come back > later with a proper fix that takes into account all platforms. > > Basically: > > * Armada XP GP is configured as RGMII-ID, and needs the PCS bit to be > set. > * Armada 370 Mirabox is configured as RGMII-ID, and needs the PCS bit > to be cleared. > > And at the moment, we don't know how to make the distinction between > those two cases. One hint is that the Armada XP GP appears in fact to > be using a QSGMII connection with the PHY (Quad-SGMII), but > configuring it as SGMII doesn't work, while RGMII-ID works. This needs > more investigation, but in the mean time, let's unbreak the network > for all those users. > > Signed-off-by: Thomas Petazzoni > Reported-by: Arnaud Ebalard > Reported-by: Alexander Reuter > Fixes: https://bugzilla.kernel.org/show_bug.cgi?id=73401 Applied, thanks for following up on this.