Re: [PATCH net] net: broadcom: Imply BROADCOM_PHY for BCMGENET

From: Marek Szyprowski
Date: Mon May 11 2020 - 03:21:58 EST


Hi Florian,

On 09.05.2020 00:32, Florian Fainelli wrote:
> The GENET controller on the Raspberry Pi 4 (2711) is typically
> interfaced with an external Broadcom PHY via a RGMII electrical
> interface. To make sure that delays are properly configured at the PHY
> side, ensure that we get a chance to have the dedicated Broadcom PHY
> driver (CONFIG_BROADCOM_PHY) enabled for this to happen.
>
> Fixes: 402482a6a78e ("net: bcmgenet: Clear ID_MODE_DIS in EXT_RGMII_OOB_CTRL when not needed")
> Reported-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>
> Signed-off-by: Florian Fainelli <f.fainelli@xxxxxxxxx>
> ---
> David,
>
> I would like Marek to indicate whether he is okay or not with this
> change. Thanks!

It is better. It fixes the default values for ARM 32bit
bcm2835_defconfig and ARM 64bit defconfig, so you can add:

Tested-by: Marek Szyprowski <m.szyprowski@xxxxxxxxxxx>

There is still an issue there. In case of ARM 64bit, when Genet driver
is configured as a module, BROADCOM_PHY is also set to module. When I
changed Genet to be built-in, BROADCOM_PHY stayed selected as module.
This case doesn't work, as Genet driver is loaded much earlier than the
rootfs/initrd/etc is available, thus broadcom phy driver is not loaded
at all. It looks that some kind of deferred probe is missing there.

Best regards
--
Marek Szyprowski, PhD
Samsung R&D Institute Poland