Re: [PATCH 5.10 000/149] 5.10.156-rc1 review

[YueHaibing <yuehaibing@huawei.com>]

On 2022/11/25 18:02, Arnd Bergmann wrote:
> On Fri, Nov 25, 2022, at 09:05, Naresh Kamboju wrote:
>> On Fri, 25 Nov 2022 at 12:57, Greg Kroah-Hartman <gregkh@linuxfoundation.org> wrote:
>>> On Thu, Nov 24, 2022 at 09:17:36PM +0530, Naresh Kamboju wrote:
>>>>
>>>> Daniel bisected this reported problem and found the first bad commit,
>>>>
>>>> YueHaibing <yuehaibing@huawei.com>
>>>>     net: broadcom: Fix BCMGENET Kconfig
>>>
>>> But that is in 5.10.155, 5.15.79, 6.0.9, and 6.1-rc5.  It is not new to
>>> this -rc release.
>>
>> It started from 5.10.155 and this is only seen on 5.10 and other
>> branches 5.15, 6.0 and mainline are looking good.
> 
> I think the original patch is wrong and should be fixed upstream.
> The backported patch in question is a one-line Kconfig change doing

It seems lts 5.10 do not contain commit e5f31552674e ("ethernet: fix PTP_1588_CLOCK dependencies"),
there is not PTP_1588_CLOCK_OPTIONAL option.

> 
> diff --git a/drivers/net/ethernet/broadcom/Kconfig b/drivers/net/ethernet/broadcom/Kconfig
> index f4e1ca68d831..55dfdb34e37b 100644
> --- a/drivers/net/ethernet/broadcom/Kconfig
> +++ b/drivers/net/ethernet/broadcom/Kconfig
> @@ -77,7 +77,7 @@ config BCMGENET
>         select BCM7XXX_PHY
>         select MDIO_BCM_UNIMAC
>         select DIMLIB
> -       select BROADCOM_PHY if ARCH_BCM2835
> +       select BROADCOM_PHY if (ARCH_BCM2835 && PTP_1588_CLOCK_OPTIONAL)
>         help
>           This driver supports the built-in Ethernet MACs found in the
>           Broadcom BCM7xxx Set Top Box family chipset.
> 
> which fixes the build on kernels that contain 99addbe31f55 ("net:
> broadcom: Select BROADCOM_PHY for BCMGENET") and enable
> BCMGENET=y but PTP_1588_CLOCK_OPTIONAL=m, which otherwise
> leads to a link failure.
> 
> The patch unfortunately solves it by replacing it with a runtime
> failure by no longer linking in the PHY driver (as found by Naresh).
> 
> I think the correct fix would be to propagate the dependency down
> to BCMGENET:
> 
> diff --git a/drivers/net/ethernet/broadcom/Kconfig b/drivers/net/ethernet/broadcom/Kconfig
> index f4e1ca68d831..f4ca0c6c0f51 100644
> --- a/drivers/net/ethernet/broadcom/Kconfig
> +++ b/drivers/net/ethernet/broadcom/Kconfig
> @@ -71,6 +71,7 @@ config BCM63XX_ENET
>  config BCMGENET
>  	tristate "Broadcom GENET internal MAC support"
>  	depends on HAS_IOMEM
> +	depends on PTP_1588_CLOCK_OPTIONAL || !ARCH_BCM2835
>  	select MII
>  	select PHYLIB
>  	select FIXED_PHY
> 
> With this change, the broken config is no longer possible, instead
> forcing BCMGENET to be =m when building for ARCH_BCM2835 with
> PTP_1588_CLOCK=m.
> 
>      Arnd
> .
>