From mboxrd@z Thu Jan 1 00:00:00 1970 From: =?utf-8?Q?Lothar_Wa=C3=9Fmann?= Subject: Re: [PATCH][NET] several cleanups and bugfixes for fec.c: preserve MII/RMII setting in fec_stop() Date: Wed, 7 Dec 2011 11:42:28 +0100 Message-ID: <20191.17172.493079.722098@ipc1.ka-ro> References: <20111207094146.GG5550@S2100-06.ap.freescale.net> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: QUOTED-PRINTABLE Cc: , Shawn Guo , , To: Shawn Guo Return-path: In-Reply-To: <20111207094146.GG5550@S2100-06.ap.freescale.net> Sender: linux-kernel-owner@vger.kernel.org List-Id: netdev.vger.kernel.org Hi, Shawn Guo writes: > On Tue, Dec 06, 2011 at 11:27:14AM +0100, Lothar Wa=C3=9Fmann 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 interf= ace >=20 > s/MII/RMII? From what I see from imx28 and imx6q RM, the reset state > for this setting is MII mode. >=20 > > functional. > >=20 > > Signed-off-by: Lothar Wa=C3=9Fmann > > --- > > drivers/net/ethernet/freescale/fec.c | 5 ++++- > > 1 files changed, 4 insertions(+), 1 deletions(-) >=20 > I assume this is fixing a problem you are seeing on imx28 only. > Do you see the problem on imx53/51? >=20 No. i.MX53 uses the RMII gasket which is not affected by resetting the controller. And imMX51 does not support RMII at all. > >=20 > > diff --git a/drivers/net/ethernet/freescale/fec.c b/drivers/net/eth= ernet/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 =3D netdev_priv(ndev); > > const struct platform_device_id *id_entry =3D > > platform_get_device_id(fep->pdev); > > + u32 rmii_mode =3D readl(fep->hwp + FEC_R_CNTRL) & (1 << 8); >=20 > 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)? >=20 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); > > =20 > > /* We have to keep ENET enabled to have MII interrupt stay workin= g */ > > - 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); > > + } > > } >=20 > 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. >=20 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 Wa=C3=9Fmann --=20 ___________________________________________________________ Ka-Ro electronics GmbH | Pascalstra=C3=9Fe 22 | D - 52076 Aachen Phone: +49 2408 1402-0 | Fax: +49 2408 1402-10 Gesch=C3=A4ftsf=C3=BChrer: Matthias Kaussen Handelsregistereintrag: Amtsgericht Aachen, HRB 4996 www.karo-electronics.de | info@karo-electronics.de ___________________________________________________________