Re: [PATCH v2] net: ethernet: ti: Remove TI_CPTS_MOD workaround

From: Clay McClure
Date: Wed May 06 2020 - 02:51:17 EST


On Tue, May 05, 2020 at 10:41:26AM +0300, Grygorii Strashko wrote:

> It's better if you send v2 not as reply to v1.

Noted, thank you, and thank you for taking the time to review my patch.

> just to clarify. After these two patches
> - the PTP_1588_CLOCK can still be set to "M"
> - which will cause TI_CPTS to be "M",
> - but TI_CPSW will still be "Y".
>
> and all above will build and produce built-in CPSW without CPTS support
> and cpts.ko which is loadable, but not functional.
>
> Sorry, I'm a little bit lost regarding the target you'are trying to achieve.
> At least previously "imply PTP_1588_CLOCK" allowed to select properly PTP_1588_CLOCK
> without modifying every defconfig.

Well, I just wanted to squelch a WARN_ON(). As Arnd pointed out in [1],
code that uses the stubbed cpts functions is supposed to gracefully
handle receiving a null pointer. Splatting a warning is not graceful,
and that's what I was trying to fix.

But your question in [2] prompted me to consider whether it should be
possible to build TI_CPTS without PTP_1588_CLOCK at all. I think the
answer is no, so I tried to fix it, but you're right, it's still
possible to end up with a nonfunctional module after my patch.

If you prefer to revert, that's fine with me. Should I post a patch, or
just ask David to revert?

--
Clay

[1]: https://lore.kernel.org/lkml/CAK8P3a22aSbpcVK-cZ6rhnPgbYEGU3z__G9xk1EexOPZd5Hmzw@xxxxxxxxxxxxxx/
[2]: https://lore.kernel.org/lkml/6fef3a00-6c18-b775-d1b4-dfd692261bd3@xxxxxx/

>
> > Reported-by: kbuild test robot <lkp@xxxxxxxxx>
> > Signed-off-by: Clay McClure <clay@xxxxxxxxxxx>
> > ---
> > Changes in v2:
> >
> > - Don't regenerate the defconfigs, just add PTP_1588_CLOCK.
> >
> > arch/arm/configs/keystone_defconfig | 1 +
> > arch/arm/configs/omap2plus_defconfig | 1 +
> > drivers/net/ethernet/ti/Kconfig | 13 ++++---------
> > drivers/net/ethernet/ti/Makefile | 2 +-
> > drivers/net/ethernet/ti/cpsw_ethtool.c | 2 +-
> > drivers/net/ethernet/ti/cpts.h | 3 +--
> > drivers/net/ethernet/ti/netcp_ethss.c | 10 +++++-----
> > 7 files changed, 14 insertions(+), 18 deletions(-)
> >
> > diff --git a/arch/arm/configs/keystone_defconfig b/arch/arm/configs/keystone_defconfig
> > index 11e2211f9007..84a3b055f253 100644
> > --- a/arch/arm/configs/keystone_defconfig
> > +++ b/arch/arm/configs/keystone_defconfig
> > @@ -147,6 +147,7 @@ CONFIG_I2C_DAVINCI=y
> > CONFIG_SPI=y
> > CONFIG_SPI_DAVINCI=y
> > CONFIG_SPI_SPIDEV=y
> > +CONFIG_PTP_1588_CLOCK=y
> > CONFIG_PINCTRL_SINGLE=y
> > CONFIG_GPIOLIB=y
> > CONFIG_GPIO_SYSFS=y
> > diff --git a/arch/arm/configs/omap2plus_defconfig b/arch/arm/configs/omap2plus_defconfig
> > index 3cc3ca5fa027..8b83d4a5d309 100644
> > --- a/arch/arm/configs/omap2plus_defconfig
> > +++ b/arch/arm/configs/omap2plus_defconfig
> > @@ -274,6 +274,7 @@ CONFIG_SPI_TI_QSPI=m
> > CONFIG_HSI=m
> > CONFIG_OMAP_SSI=m
> > CONFIG_SSI_PROTOCOL=m
> > +CONFIG_PTP_1588_CLOCK=y
> > CONFIG_PINCTRL_SINGLE=y
> > CONFIG_DEBUG_GPIO=y
> > CONFIG_GPIO_SYSFS=y
> > diff --git a/drivers/net/ethernet/ti/Kconfig b/drivers/net/ethernet/ti/Kconfig
> > index 8e348780efb6..f3f8bb724294 100644
> > --- a/drivers/net/ethernet/ti/Kconfig
> > +++ b/drivers/net/ethernet/ti/Kconfig
> > @@ -77,23 +77,18 @@ config TI_CPSW_SWITCHDEV
> > will be called cpsw_new.
> > config TI_CPTS
> > - bool "TI Common Platform Time Sync (CPTS) Support"
> > + tristate "TI Common Platform Time Sync (CPTS) Support"
> > depends on TI_CPSW || TI_KEYSTONE_NETCP || TI_CPSW_SWITCHDEV || COMPILE_TEST
> > depends on COMMON_CLK
> > - depends on POSIX_TIMERS
> > + depends on PTP_1588_CLOCK
>
> > + default y if TI_CPSW=y || TI_KEYSTONE_NETCP=y || TI_CPSW_SWITCHDEV=y
>
> even with above statement it's possible to force TI_CPTS="M" while CPSW/NETCP="Y"
>
> > + default m
>
> I could be mistaken by above 2 lines seems can be 'imply TI_CPTS'
> in TI_CPSW, TI_KEYSTONE_NETCP, TI_CPSW_SWITCHDEV
>
> > ---help---
> > This driver supports the Common Platform Time Sync unit of
> > the CPSW Ethernet Switch and Keystone 2 1g/10g Switch Subsystem.
> > The unit can time stamp PTP UDP/IPv4 and Layer 2 packets, and the
> > driver offers a PTP Hardware Clock.
> > -config TI_CPTS_MOD
> > - tristate
> > - depends on TI_CPTS
> > - depends on PTP_1588_CLOCK
> > - default y if TI_CPSW=y || TI_KEYSTONE_NETCP=y || TI_CPSW_SWITCHDEV=y
> > - default m
>
> and this prevented user from forcing TI_CPTS="M" while CPSW/NETCP="Y"
>
> > -
> > config TI_K3_AM65_CPSW_NUSS
> > tristate "TI K3 AM654x/J721E CPSW Ethernet driver"
> > depends on ARCH_K3 && OF && TI_K3_UDMA_GLUE_LAYER
> > diff --git a/drivers/net/ethernet/ti/Makefile b/drivers/net/ethernet/ti/Makefile
> > index 53792190e9c2..cb26a9d21869 100644
>
> Below small diff should fix build fail:
> diff --git a/drivers/net/ethernet/ti/Kconfig b/drivers/net/ethernet/ti/Kconfig
> index 8e348780efb6..eeaee47598aa 100644
> --- a/drivers/net/ethernet/ti/Kconfig
> +++ b/drivers/net/ethernet/ti/Kconfig
> @@ -81,6 +81,7 @@ config TI_CPTS
> depends on TI_CPSW || TI_KEYSTONE_NETCP || TI_CPSW_SWITCHDEV || COMPILE_TEST
> depends on COMMON_CLK
> depends on POSIX_TIMERS
> + depends on PTP_1588_CLOCK
> ---help---
> This driver supports the Common Platform Time Sync unit of
> the CPSW Ethernet Switch and Keystone 2 1g/10g Switch Subsystem.
> @@ -90,7 +91,6 @@ config TI_CPTS
> config TI_CPTS_MOD
> tristate
> depends on TI_CPTS
> - depends on PTP_1588_CLOCK
> default y if TI_CPSW=y || TI_KEYSTONE_NETCP=y || TI_CPSW_SWITCHDEV=y
> default m
>
> Then separate patch can be used to enable PTP_1588_CLOCK in defconfigs.
>
> My personal opinion - it might be better to revert TI CPTS part from
> b6d49cab44b5 ("net: Make PTP-specific drivers depend on PTP_1588_CLOCK")
> at all.
>
> --
> Best regards,
> grygorii