[PATCH] net: broadcom: Add PTP_1588_CLOCK_OPTIONAL dependency for BCMGENET under ARCH_BCM2835

[PATCH] net: broadcom: Add PTP_1588_CLOCK_OPTIONAL dependency for BCMGENET under ARCH_BCM2835

[YueHaibing]

commit 8d820bc9d12b ("net: broadcom: Fix BCMGENET Kconfig") fixes the build
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. However this may trigger a runtime failure.

Fix the original issue by propagating the PTP_1588_CLOCK_OPTIONAL dependency
of BROADCOM_PHY down to BCMGENET.

Fixes: 8d820bc9d12b ("net: broadcom: Fix BCMGENET Kconfig")
Fixes: 99addbe31f55 ("net: broadcom: Select BROADCOM_PHY for BCMGENET")
Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
Suggested-by: Arnd Bergmann <arnd@arndb.de>
Signed-off-by: YueHaibing <yuehaibing@huawei.com>
---
 drivers/net/ethernet/broadcom/Kconfig | 3 ++-
 1 file changed, 2 insertions(+), 1 deletion(-)

diff --git a/drivers/net/ethernet/broadcom/Kconfig b/drivers/net/ethernet/broadcom/Kconfig
index 55dfdb34e37b..f4ca0c6c0f51 100644
--- a/drivers/net/ethernet/broadcom/Kconfig
+++ b/drivers/net/ethernet/broadcom/Kconfig
@@ -71,13 +71,14 @@ 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
 	select BCM7XXX_PHY
 	select MDIO_BCM_UNIMAC
 	select DIMLIB
-	select BROADCOM_PHY if (ARCH_BCM2835 && PTP_1588_CLOCK_OPTIONAL)
+	select BROADCOM_PHY if ARCH_BCM2835
 	help
 	  This driver supports the built-in Ethernet MACs found in the
 	  Broadcom BCM7xxx Set Top Box family chipset.
-- 
2.17.1

Re: [PATCH] net: broadcom: Add PTP_1588_CLOCK_OPTIONAL dependency for BCMGENET under ARCH_BCM2835

[Arnd Bergmann]

On Fri, Nov 25, 2022, at 12:50, YueHaibing wrote:
> commit 8d820bc9d12b ("net: broadcom: Fix BCMGENET Kconfig") fixes the build
> 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. However this may trigger a runtime failure.
>
> Fix the original issue by propagating the PTP_1588_CLOCK_OPTIONAL dependency
> of BROADCOM_PHY down to BCMGENET.
>
> Fixes: 8d820bc9d12b ("net: broadcom: Fix BCMGENET Kconfig")
> Fixes: 99addbe31f55 ("net: broadcom: Select BROADCOM_PHY for BCMGENET")
> Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
> Suggested-by: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: YueHaibing <yuehaibing@huawei.com>

Thanks for fixing this,

Acked-by: Arnd Bergmann <arnd@arndb.de>

Re: [PATCH] net: broadcom: Add PTP_1588_CLOCK_OPTIONAL dependency for BCMGENET under ARCH_BCM2835

[Jakub Kicinski]

On Fri, 25 Nov 2022 19:50:03 +0800 YueHaibing wrote:
> commit 8d820bc9d12b ("net: broadcom: Fix BCMGENET Kconfig") fixes the build
> 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. However this may trigger a runtime failure.
> 
> Fix the original issue by propagating the PTP_1588_CLOCK_OPTIONAL dependency
> of BROADCOM_PHY down to BCMGENET.
> 
> Fixes: 8d820bc9d12b ("net: broadcom: Fix BCMGENET Kconfig")
> Fixes: 99addbe31f55 ("net: broadcom: Select BROADCOM_PHY for BCMGENET")
> Reported-by: Naresh Kamboju <naresh.kamboju@linaro.org>
> Suggested-by: Arnd Bergmann <arnd@arndb.de>
> Signed-off-by: YueHaibing <yuehaibing@huawei.com>
> ---
>  drivers/net/ethernet/broadcom/Kconfig | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/broadcom/Kconfig b/drivers/net/ethernet/broadcom/Kconfig
> index 55dfdb34e37b..f4ca0c6c0f51 100644
> --- a/drivers/net/ethernet/broadcom/Kconfig
> +++ b/drivers/net/ethernet/broadcom/Kconfig
> @@ -71,13 +71,14 @@ 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
>  	select BCM7XXX_PHY
>  	select MDIO_BCM_UNIMAC
>  	select DIMLIB
> -	select BROADCOM_PHY if (ARCH_BCM2835 && PTP_1588_CLOCK_OPTIONAL)
> +	select BROADCOM_PHY if ARCH_BCM2835
>  	help
>  	  This driver supports the built-in Ethernet MACs found in the
>  	  Broadcom BCM7xxx Set Top Box family chipset.

What's the code path that leads to the failure? I want to double check
that the driver is handling the PTP registration return codes correctly.
IIUC this is a source of misunderstandings in the PTP API.

Richard, here's the original report:
https://lore.kernel.org/all/CA+G9fYvKfbJHcMZtybf_0Ru3+6fKPg9HwWTOhdCLrOBXMaeG1A@mail.gmail.com/

Re: [PATCH] net: broadcom: Add PTP_1588_CLOCK_OPTIONAL dependency for BCMGENET under ARCH_BCM2835

[Arnd Bergmann]

On Tue, Nov 29, 2022, at 04:18, Jakub Kicinski wrote:
> On Fri, 25 Nov 2022 19:50:03 +0800 YueHaibing wrote:
>> diff --git a/drivers/net/ethernet/broadcom/Kconfig b/drivers/net/ethernet/broadcom/Kconfig
>> index 55dfdb34e37b..f4ca0c6c0f51 100644
>> --- a/drivers/net/ethernet/broadcom/Kconfig
>> +++ b/drivers/net/ethernet/broadcom/Kconfig
>> @@ -71,13 +71,14 @@ 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
>>  	select BCM7XXX_PHY
>>  	select MDIO_BCM_UNIMAC
>>  	select DIMLIB
>> -	select BROADCOM_PHY if (ARCH_BCM2835 && PTP_1588_CLOCK_OPTIONAL)
>> +	select BROADCOM_PHY if ARCH_BCM2835
>>  	help
>>  	  This driver supports the built-in Ethernet MACs found in the
>>  	  Broadcom BCM7xxx Set Top Box family chipset.
>
> What's the code path that leads to the failure? I want to double check
> that the driver is handling the PTP registration return codes correctly.
> IIUC this is a source of misunderstandings in the PTP API.
>
> Richard, here's the original report:
> https://lore.kernel.org/all/CA+G9fYvKfbJHcMZtybf_0Ru3+6fKPg9HwWTOhdCLrOBXMaeG1A@mail.gmail.com

The original report was for a different bug that resulted in the
BROADCOM_PHY driver not being selectable at all.

The remaining problem here is this configuration:

CONFIG_ARM=y
CONFIG_BCM2835=y
CONFIG_BCMGENET=y
CONFIG_PTP_1588_CLOCK=m
CONFIG_PTP_1588_CLOCK_OPTIONAL=m
CONFIG_BROADCOM_PHY=m

In this case, BCMGENET should 'select BROADCOM_PHY' to make the
driver work correctly, but fails to do this because of the
dependency. During early boot, this means it cannot access the
PHY because that is in a loadable module, despite commit
99addbe31f55 ("net: broadcom: Select BROADCOM_PHY for BCMGENET")
trying to ensure that it could.

Note that many other ethernet drivers don't have this
particular 'select' statement and just rely on the .config
to contain a sensible set of drivers. In particular that
is true when running 64-bit kernels on the same chip,
which is now the normal configuration.

The alternative to YueHaibing's fix would be to just revert
99addbe31f55 ("net: broadcom: Select BROADCOM_PHY for BCMGENET")
and instead change the defconfig file to include the phy driver,
as we do elsewhere.

    Arnd

Re: [PATCH] net: broadcom: Add PTP_1588_CLOCK_OPTIONAL dependency for BCMGENET under ARCH_BCM2835

[Arnd Bergmann]

[Florian's broadcom.com address bounces, adding him to Cc
with his gmail address]

On Tue, Nov 29, 2022, at 12:56, Arnd Bergmann wrote:
> On Tue, Nov 29, 2022, at 04:18, Jakub Kicinski wrote:
>> On Fri, 25 Nov 2022 19:50:03 +0800 YueHaibing wrote:
>>> diff --git a/drivers/net/ethernet/broadcom/Kconfig b/drivers/net/ethernet/broadcom/Kconfig
>>> index 55dfdb34e37b..f4ca0c6c0f51 100644
>>> --- a/drivers/net/ethernet/broadcom/Kconfig
>>> +++ b/drivers/net/ethernet/broadcom/Kconfig
>>> @@ -71,13 +71,14 @@ 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
>>>  	select BCM7XXX_PHY
>>>  	select MDIO_BCM_UNIMAC
>>>  	select DIMLIB
>>> -	select BROADCOM_PHY if (ARCH_BCM2835 && PTP_1588_CLOCK_OPTIONAL)
>>> +	select BROADCOM_PHY if ARCH_BCM2835
>>>  	help
>>>  	  This driver supports the built-in Ethernet MACs found in the
>>>  	  Broadcom BCM7xxx Set Top Box family chipset.
>>
>> What's the code path that leads to the failure? I want to double check
>> that the driver is handling the PTP registration return codes correctly.
>> IIUC this is a source of misunderstandings in the PTP API.
>>
>> Richard, here's the original report:
>> https://lore.kernel.org/all/CA+G9fYvKfbJHcMZtybf_0Ru3+6fKPg9HwWTOhdCLrOBXMaeG1A@mail.gmail.com
>
> The original report was for a different bug that resulted in the
> BROADCOM_PHY driver not being selectable at all.
>
> The remaining problem here is this configuration:
>
> CONFIG_ARM=y
> CONFIG_BCM2835=y
> CONFIG_BCMGENET=y
> CONFIG_PTP_1588_CLOCK=m
> CONFIG_PTP_1588_CLOCK_OPTIONAL=m
> CONFIG_BROADCOM_PHY=m
>
> In this case, BCMGENET should 'select BROADCOM_PHY' to make the
> driver work correctly, but fails to do this because of the
> dependency. During early boot, this means it cannot access the
> PHY because that is in a loadable module, despite commit
> 99addbe31f55 ("net: broadcom: Select BROADCOM_PHY for BCMGENET")
> trying to ensure that it could.
>
> Note that many other ethernet drivers don't have this
> particular 'select' statement and just rely on the .config
> to contain a sensible set of drivers. In particular that
> is true when running 64-bit kernels on the same chip,
> which is now the normal configuration.
>
> The alternative to YueHaibing's fix would be to just revert
> 99addbe31f55 ("net: broadcom: Select BROADCOM_PHY for BCMGENET")
> and instead change the defconfig file to include the phy driver,
> as we do elsewhere.
>
>     Arnd

Re: [PATCH] net: broadcom: Add PTP_1588_CLOCK_OPTIONAL dependency for BCMGENET under ARCH_BCM2835

[Florian Fainelli]

On 11/29/22 03:58, Arnd Bergmann wrote:
> [Florian's broadcom.com address bounces, adding him to Cc
> with his gmail address]

Yes, because it's not a valid email address :) it's either lastname, or 
first.lastname.

> 
> On Tue, Nov 29, 2022, at 12:56, Arnd Bergmann wrote:
>> On Tue, Nov 29, 2022, at 04:18, Jakub Kicinski wrote:
>>> On Fri, 25 Nov 2022 19:50:03 +0800 YueHaibing wrote:
>>>> diff --git a/drivers/net/ethernet/broadcom/Kconfig b/drivers/net/ethernet/broadcom/Kconfig
>>>> index 55dfdb34e37b..f4ca0c6c0f51 100644
>>>> --- a/drivers/net/ethernet/broadcom/Kconfig
>>>> +++ b/drivers/net/ethernet/broadcom/Kconfig
>>>> @@ -71,13 +71,14 @@ 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
>>>>   	select BCM7XXX_PHY
>>>>   	select MDIO_BCM_UNIMAC
>>>>   	select DIMLIB
>>>> -	select BROADCOM_PHY if (ARCH_BCM2835 && PTP_1588_CLOCK_OPTIONAL)
>>>> +	select BROADCOM_PHY if ARCH_BCM2835
>>>>   	help
>>>>   	  This driver supports the built-in Ethernet MACs found in the
>>>>   	  Broadcom BCM7xxx Set Top Box family chipset.
>>>
>>> What's the code path that leads to the failure? I want to double check
>>> that the driver is handling the PTP registration return codes correctly.
>>> IIUC this is a source of misunderstandings in the PTP API.
>>>
>>> Richard, here's the original report:
>>> https://lore.kernel.org/all/CA+G9fYvKfbJHcMZtybf_0Ru3+6fKPg9HwWTOhdCLrOBXMaeG1A@mail.gmail.com
>>
>> The original report was for a different bug that resulted in the
>> BROADCOM_PHY driver not being selectable at all.
>>
>> The remaining problem here is this configuration:
>>
>> CONFIG_ARM=y
>> CONFIG_BCM2835=y
>> CONFIG_BCMGENET=y
>> CONFIG_PTP_1588_CLOCK=m
>> CONFIG_PTP_1588_CLOCK_OPTIONAL=m
>> CONFIG_BROADCOM_PHY=m
>>
>> In this case, BCMGENET should 'select BROADCOM_PHY' to make the
>> driver work correctly, but fails to do this because of the
>> dependency. During early boot, this means it cannot access the
>> PHY because that is in a loadable module, despite commit
>> 99addbe31f55 ("net: broadcom: Select BROADCOM_PHY for BCMGENET")
>> trying to ensure that it could.

I don't believe this is the failure mechanism because there is always a 
fallback to the Generic PHY driver, the issue is that we have configured 
a specific RGMII mode in the Device Tree that is acted on by both the 
Ethernet MAC and the PHY in a way that is electrically incompatible 
unless the proper PHY driver is also enabled such that the RGMII mode is 
enabled on the PHY side.
-- 
Florian

Re: [PATCH] net: broadcom: Add PTP_1588_CLOCK_OPTIONAL dependency for BCMGENET under ARCH_BCM2835

[Jakub Kicinski]

On Tue, 29 Nov 2022 12:58:23 +0100 Arnd Bergmann wrote:
> > The original report was for a different bug that resulted in the
> > BROADCOM_PHY driver not being selectable at all.
> >
> > The remaining problem here is this configuration:
> >
> > CONFIG_ARM=y
> > CONFIG_BCM2835=y
> > CONFIG_BCMGENET=y
> > CONFIG_PTP_1588_CLOCK=m
> > CONFIG_PTP_1588_CLOCK_OPTIONAL=m
> > CONFIG_BROADCOM_PHY=m
> >
> > In this case, BCMGENET should 'select BROADCOM_PHY' to make the
> > driver work correctly, but fails to do this because of the
> > dependency. During early boot, this means it cannot access the
> > PHY because that is in a loadable module, despite commit
> > 99addbe31f55 ("net: broadcom: Select BROADCOM_PHY for BCMGENET")
> > trying to ensure that it could.
> >
> > Note that many other ethernet drivers don't have this
> > particular 'select' statement and just rely on the .config
> > to contain a sensible set of drivers. In particular that
> > is true when running 64-bit kernels on the same chip,
> > which is now the normal configuration.
> >
> > The alternative to YueHaibing's fix would be to just revert
> > 99addbe31f55 ("net: broadcom: Select BROADCOM_PHY for BCMGENET")
> > and instead change the defconfig file to include the phy driver,
> > as we do elsewhere.

Ah, got it now, I think. Alternatively we could flip the 'select' to 
'depends on' and make the user do the legwork? Enough brain cycles
spend on this simple fix tho, so applying, thanks! :)

Re: [PATCH] net: broadcom: Add PTP_1588_CLOCK_OPTIONAL dependency for BCMGENET under ARCH_BCM2835

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net.git (master)
by Jakub Kicinski <kuba@kernel.org>:

On Fri, 25 Nov 2022 19:50:03 +0800 you wrote:
> commit 8d820bc9d12b ("net: broadcom: Fix BCMGENET Kconfig") fixes the build
> 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. However this may trigger a runtime failure.
> 
> Fix the original issue by propagating the PTP_1588_CLOCK_OPTIONAL dependency
> of BROADCOM_PHY down to BCMGENET.
> 
> [...]

Here is the summary with links:
  - net: broadcom: Add PTP_1588_CLOCK_OPTIONAL dependency for BCMGENET under ARCH_BCM2835
    https://git.kernel.org/netdev/net/c/421f8663b3a7

You are awesome, thank you!
-- 
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