Hi
On 25.02.2020 14:11, Nicolas Saenz Julienne wrote:
> Outdated Raspberry Pi 4 firmware might configure the external PHY as
> rgmii although the kernel currently sets it as rgmii-rxid. This makes
> connections unreliable as ID_MODE_DIS is left enabled. To avoid this,
> explicitly clear that bit whenever we don't need it.
>
> Fixes: da38802211cc ("net: bcmgenet: Add RGMII_RXID support")
> Signed-off-by: Nicolas Saenz Julienne <nsaenzjulie...@suse.de>
I've finally bisected the network issue I have on my RPi4 used for
testing mainline builds. The bisect pointed to this patch. Once it got
applied in v5.7-rc1, the networking is broken on my RPi4 in ARM32bit
mode and kernel compiled from bcm2835_defconfig. I'm using u-boot to
tftp zImage/dtb/initrd there. After reverting this patch network is
working fine again. The strange thing is that networking works fine if
kernel is compiled from multi_v7_defconfig but I don't see any obvious
difference there.
I'm not sure if u-boot is responsible for this break, but kernel
definitely should be able to properly reset the hardware to the valid state.
I can provide more information, just let me know what is needed. Here is
the log, I hope it helps:
[ 11.881784] bcmgenet fd580000.ethernet eth0: Link is Up - 1Gbps/Full
- flow control off
[ 11.889935] IPv6: ADDRCONF(NETDEV_CHANGE): eth0: link becomes ready
root@target:~# ping host
PING host (192.168.100.1) 56(84) bytes of data.
From 192.168.100.53 icmp_seq=1 Destination Host Unreachable
...
> ---
>
> Changes since v1:
> - Fix tags ordering
> - Add targeted tree
>
> drivers/net/ethernet/broadcom/genet/bcmmii.c | 1 +
> 1 file changed, 1 insertion(+)
>
> diff --git a/drivers/net/ethernet/broadcom/genet/bcmmii.c
> b/drivers/net/ethernet/broadcom/genet/bcmmii.c
> index 6392a2530183..10244941a7a6 100644
> --- a/drivers/net/ethernet/broadcom/genet/bcmmii.c
> +++ b/drivers/net/ethernet/broadcom/genet/bcmmii.c
> @@ -294,6 +294,7 @@ int bcmgenet_mii_config(struct net_device *dev, bool init)
> */
> if (priv->ext_phy) {
> reg = bcmgenet_ext_readl(priv, EXT_RGMII_OOB_CTRL);
> + reg &= ~ID_MODE_DIS;
> reg |= id_mode_dis;
> if (GENET_IS_V1(priv) || GENET_IS_V2(priv) || GENET_IS_V3(priv))
> reg |= RGMII_MODE_EN_V123;
Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland
