RE: [PATCH resubmit 3] net: fec: Fix FEC_ECR_EN1588 being cleared on link-down

[Wei Fang]

> -----Original Message-----
> From: Csókás, Bence <csokas.bence@xxxxxxxxx>
> Sent: 2024年6月19日 20:31
> To: Frank Li <Frank.Li@xxxxxxxxxxxxx>; David S. Miller
> <davem@xxxxxxxxxxxxx>; imx@xxxxxxxxxxxxxxx; netdev@xxxxxxxxxxxxxxx;
> linux-kernel@xxxxxxxxxxxxxxx
> Cc: Csókás, Bence <csokas.bence@xxxxxxxxx>; Richard Cochran
> <richardcochran@xxxxxxxxx>; Andrew Lunn <andrew@xxxxxxx>; Wei Fang
> <wei.fang@xxxxxxx>; Shenwei Wang <shenwei.wang@xxxxxxx>; Clark
> Wang <xiaoning.wang@xxxxxxx>; Eric Dumazet <edumazet@xxxxxxxxxx>;
> Jakub Kicinski <kuba@xxxxxxxxxx>; Paolo Abeni <pabeni@xxxxxxxxxx>
> Subject: [PATCH resubmit 3] net: fec: Fix FEC_ECR_EN1588 being cleared on
> link-down
>
> FEC_ECR_EN1588 bit gets cleared after MAC reset in `fec_stop()`, which
> makes all 1588 functionality shut down, and all the extended registers
> disappear, on link-down, making the adapter fall back to compatibility "dumb
> mode". However, some functionality needs to be retained (e.g. PPS) even
> without link.
>
> Fixes: 6605b730c061 ("FEC: Add time stamping code and a PTP hardware
> clock")
> Cc: Richard Cochran <richardcochran@xxxxxxxxx>
> Reviewed-by: Andrew Lunn <andrew@xxxxxxx>
> Link:
> https://lore.ker/
> nel.org%2Fnetdev%2F5fa9fadc-a89d-467a-aae9-c65469ff5fe1%40lunn.ch%2F
> &data=05%7C02%7Cwei.fang%40nxp.com%7C68af958c8a3545b457c408dc90
> 5c129b%7C686ea1d3bc2b4c6fa92cd99c5c301635%7C0%7C0%7C6385439723
> 35606813%7CUnknown%7CTWFpbGZsb3d8eyJWIjoiMC4wLjAwMDAiLCJQIjoiV
> 2luMzIiLCJBTiI6Ik1haWwiLCJXVCI6Mn0%3D%7C0%7C%7C%7C&sdata=GfV0Lj
> 6k5RwRLUArRhbxaDoNpG6wLlZSQh9vNxuReZA%3D&reserved=0
> Signed-off-by: Csókás, Bence <csokas.bence@xxxxxxxxx>
> ---
>  drivers/net/ethernet/freescale/fec_main.c | 6 ++++++
>  1 file changed, 6 insertions(+)
>
> diff --git a/drivers/net/ethernet/freescale/fec_main.c
> b/drivers/net/ethernet/freescale/fec_main.c
> index 881ece735dcf..fb19295529a2 100644
> --- a/drivers/net/ethernet/freescale/fec_main.c
> +++ b/drivers/net/ethernet/freescale/fec_main.c
> @@ -1361,6 +1361,12 @@ fec_stop(struct net_device *ndev)
>               writel(FEC_ECR_ETHEREN, fep->hwp + FEC_ECNTRL);
>               writel(rmii_mode, fep->hwp + FEC_R_CNTRL);
>       }
> +
> +     if (fep->bufdesc_ex) {
> +             val = readl(fep->hwp + FEC_ECNTRL);
> +             val |= FEC_ECR_EN1588;
> +             writel(val, fep->hwp + FEC_ECNTRL);
> +     }
>  }
>
>  static void
> --
> 2.34.1
>

Thank you!

Reviewed-by: Wei Fang <wei.fang@xxxxxxx>