Hi, > From: Lothar Waßmann <l...@karo-electronics.de> Sent: Friday, November 27, > 2015 9:39 PM > > To: Andrew Lunn; David S. Miller; Estevam Fabio-R49496; Kevin Hao; Lothar > > Waßmann; Lucas Stach; Duan Fugang-B38611; Philippe Reynes; Russell King; > > Uwe Kleine-König; linux-ker...@vger.kernel.org; netdev@vger.kernel.org; > > Stefan Agner > > Subject: [PATCH] net: fec: fix enet_out clock handling > > > > When ENET_OUT is being used as reference clock for an external PHY, the > > clock must not be disabled while the PHY is active. Otherwise the PHY may > > lose its internal state and require a reset to become functional again. > > > > A symptom for this bug is a network interface that constantly toggles > > between UP and DOWN state: > > fec 800f0000.ethernet eth0: Link is Up - 100Mbps/Full - flow control > > rx/tx fec 800f0000.ethernet eth0: Link is Down fec 800f0000.ethernet eth0: > > Link is Up - 100Mbps/Full - flow control rx/tx fec 800f0000.ethernet eth0: > > Link is Down [...] > > > > Signed-off-by: Lothar Waßmann <l...@karo-electronics.de> > > --- > > drivers/net/ethernet/freescale/fec_main.c | 34 +++++++++++++------------ > > ------ > > 1 file changed, 14 insertions(+), 20 deletions(-) > > > > When MAC is not ready with clocks disabled, it is not necessary to supply > clock for PHY. In fact, PHY also is not ready, why does it need clock ? > For your problem, you must add PHY reset in your dts file to resolve your > problem. > The phy-reset-gpio property is set in the DTB. But fec_reset_phy() which asserts the RESET is only called from within the probe() function. It should probably be called from fec_restart() instead?
Lothar Waßmann -- To unsubscribe from this list: send the line "unsubscribe netdev" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
