[PATCH][NET] several cleanups and bugfixes for fec.c: preserve MII/RMII setting in fec_stop()

Shawn Guo
2011-12-07T09:41:48Z

On Tue, Dec 06, 2011 at 11:27:14AM +0100, Lothar Wa?mann 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 Wa?mann <LW@KARO-electronics.de>
> ---
> 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?

>
> 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)?

>
> /* 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.

--
Regards,
Shawn