From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754972Ab1LGKmf (ORCPT ); Wed, 7 Dec 2011 05:42:35 -0500 Received: from mail.karo-electronics.de ([81.173.242.67]:56128 "EHLO mail.karo-electronics.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753825Ab1LGKme (ORCPT ); Wed, 7 Dec 2011 05:42:34 -0500 Message-ID: <20191.17172.493079.722098@ipc1.ka-ro> Date: Wed, 7 Dec 2011 11:42:28 +0100 From: =?utf-8?Q?Lothar_Wa=C3=9Fmann?= To: Shawn Guo Cc: , Shawn Guo , , Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: 8bit Subject: Re: [PATCH][NET] several cleanups and bugfixes for fec.c: preserve MII/RMII setting in fec_stop() In-Reply-To: <20111207094146.GG5550@S2100-06.ap.freescale.net> References: <20111207094146.GG5550@S2100-06.ap.freescale.net> X-Mailer: VM 8.0.9 under Emacs 22.2.1 (i486-pc-linux-gnu) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Hi, Shawn Guo writes: > On Tue, Dec 06, 2011 at 11:27:14AM +0100, Lothar Waßmann wrote: > > Additionally to setting the ETHER_EN bit in FEC_ECNTRL the MII/RMII > > setting in FEC_R_CNTRL needs to be preserved to keep the MII interface > > s/MII/RMII? From what I see from imx28 and imx6q RM, the reset state > for this setting is MII mode. > > > functional. > > > > Signed-off-by: Lothar Waßmann > > --- > > drivers/net/ethernet/freescale/fec.c | 5 ++++- > > 1 files changed, 4 insertions(+), 1 deletions(-) > > I assume this is fixing a problem you are seeing on imx28 only. > Do you see the problem on imx53/51? > No. i.MX53 uses the RMII gasket which is not affected by resetting the controller. And imMX51 does not support RMII at all. > > > > diff --git a/drivers/net/ethernet/freescale/fec.c b/drivers/net/ethernet/freescale/fec.c > > index 11534b9..ab0afb5 100644 > > --- a/drivers/net/ethernet/freescale/fec.c > > +++ b/drivers/net/ethernet/freescale/fec.c > > @@ -515,6 +515,7 @@ fec_stop(struct net_device *ndev) > > struct fec_enet_private *fep = netdev_priv(ndev); > > const struct platform_device_id *id_entry = > > platform_get_device_id(fep->pdev); > > + u32 rmii_mode = readl(fep->hwp + FEC_R_CNTRL) & (1 << 8); > > This bit is only available on ENET (imx28 and imx6q). Do we want to > do the same thing for FEC (imx25/27/35/51/53)? > No. AFAICT that's not necessary there. > > /* We cannot expect a graceful transmit stop without link !!! */ > > if (fep->link) { > > @@ -531,8 +532,10 @@ fec_stop(struct net_device *ndev) > > writel(FEC_DEFAULT_IMASK, fep->hwp + FEC_IMASK); > > > > /* We have to keep ENET enabled to have MII interrupt stay working */ > > - if (id_entry->driver_data & FEC_QUIRK_ENET_MAC) > > + if (id_entry->driver_data & FEC_QUIRK_ENET_MAC) { > > writel(2, fep->hwp + FEC_ECNTRL); > > + writel(rmii_mode, fep->hwp + FEC_R_CNTRL); > > + } > > } > > On imx6q, we have two bits, bit 6 and 8 of FEC_R_CNTRL, to select MII > interface among MII, RMII and RGMII modes. I'm not sure if we will > run into the same problem for RGMII mode. What's your test setup? > I would try to reproduce it here. > I'm using a TX28 which has the Ethernet PHY connected in RMII mode. You should see the problem, if you unplug the ethernet cable on a configured link. Without this patch the kernel will not detect when the cable is plugged back in. Lothar Waßmann -- ___________________________________________________________ Ka-Ro electronics GmbH | Pascalstraße 22 | D - 52076 Aachen Phone: +49 2408 1402-0 | Fax: +49 2408 1402-10 Geschäftsführer: Matthias Kaussen Handelsregistereintrag: Amtsgericht Aachen, HRB 4996 www.karo-electronics.de | info@karo-electronics.de ___________________________________________________________