[PATCH] ptp: ocp: don't allow on S390

[PATCH] ptp: ocp: don't allow on S390

[Randy Dunlap]

Fix kconfig warning on arch/s390/:

WARNING: unmet direct dependencies detected for SERIAL_8250
  Depends on [n]: TTY [=y] && HAS_IOMEM [=y] && !S390 [=y]
  Selected by [m]:
  - PTP_1588_CLOCK_OCP [=m] && PTP_1588_CLOCK [=m] && HAS_IOMEM [=y] && PCI [=y] && SPI [=y] && I2C [=m] && MTD [=m]

Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Cc: Richard Cochran <richardcochran@gmail.com>
Cc: Jonathan Lemon <jonathan.lemon@gmail.com>
---
There is no 8250 serial on S390. See commit 1598e38c0770.
Is this driver useful even without 8250 serial?

 drivers/ptp/Kconfig |    1 +
 1 file changed, 1 insertion(+)

--- linux-next-20210813.orig/drivers/ptp/Kconfig
+++ linux-next-20210813/drivers/ptp/Kconfig
@@ -158,6 +158,7 @@ config PTP_1588_CLOCK_OCP
 	depends on PTP_1588_CLOCK
 	depends on HAS_IOMEM && PCI
 	depends on SPI && I2C && MTD
+	depends on !S390
 	imply SPI_MEM
 	imply SPI_XILINX
 	imply MTD_SPI_NOR

Re: [PATCH] ptp: ocp: don't allow on S390

[patchwork-bot+netdevbpf]

Hello:

This patch was applied to netdev/net-next.git (refs/heads/master):

On Fri, 13 Aug 2021 13:30:26 -0700 you wrote:
> Fix kconfig warning on arch/s390/:
> 
> WARNING: unmet direct dependencies detected for SERIAL_8250
>   Depends on [n]: TTY [=y] && HAS_IOMEM [=y] && !S390 [=y]
>   Selected by [m]:
>   - PTP_1588_CLOCK_OCP [=m] && PTP_1588_CLOCK [=m] && HAS_IOMEM [=y] && PCI [=y] && SPI [=y] && I2C [=m] && MTD [=m]
> 
> [...]

Here is the summary with links:
  - ptp: ocp: don't allow on S390
    https://git.kernel.org/netdev/net-next/c/944f510176eb

You are awesome, thank you!
--
Deet-doot-dot, I am a bot.
https://korg.docs.kernel.org/patchwork/pwbot.html

Re: [PATCH] ptp: ocp: don't allow on S390

[Jonathan Lemon]

On Fri, Aug 13, 2021 at 01:30:26PM -0700, Randy Dunlap wrote:
> There is no 8250 serial on S390. See commit 1598e38c0770.

There's a 8250 serial device on the PCI card.   Its been
ages since I've worked on the architecture, but does S390
even support PCI?

> Is this driver useful even without 8250 serial?

The FB timecard has an FPGA that will internally parse the 
GNSS strings and correct the clock, so the PTP clock will
work even without the serial devices.

However, there are userspace tools which want to read the
GNSS signal (for holdolver and leap second indication), 
which is why they are exposed.
-- 
Jonathan

Re: [PATCH] ptp: ocp: don't allow on S390

[Randy Dunlap]

On 8/16/21 2:09 PM, Jonathan Lemon wrote:
> On Fri, Aug 13, 2021 at 01:30:26PM -0700, Randy Dunlap wrote:
>> There is no 8250 serial on S390. See commit 1598e38c0770.
> 
> There's a 8250 serial device on the PCI card.   Its been
> ages since I've worked on the architecture, but does S390
> even support PCI?

Yes, it does.

>> Is this driver useful even without 8250 serial?
> 
> The FB timecard has an FPGA that will internally parse the
> GNSS strings and correct the clock, so the PTP clock will
> work even without the serial devices.
> 
> However, there are userspace tools which want to read the
> GNSS signal (for holdolver and leap second indication),
> which is why they are exposed.

So what do you recommend here?

thanks.
-- 
~Randy

Re: [PATCH] ptp: ocp: don't allow on S390

[Jonathan Lemon]

On Mon, Aug 16, 2021 at 02:15:51PM -0700, Randy Dunlap wrote:
> On 8/16/21 2:09 PM, Jonathan Lemon wrote:
> > On Fri, Aug 13, 2021 at 01:30:26PM -0700, Randy Dunlap wrote:
> > > There is no 8250 serial on S390. See commit 1598e38c0770.
> > 
> > There's a 8250 serial device on the PCI card.   Its been
> > ages since I've worked on the architecture, but does S390
> > even support PCI?
> 
> Yes, it does.
> 
> > > Is this driver useful even without 8250 serial?
> > 
> > The FB timecard has an FPGA that will internally parse the
> > GNSS strings and correct the clock, so the PTP clock will
> > work even without the serial devices.
> > 
> > However, there are userspace tools which want to read the
> > GNSS signal (for holdolver and leap second indication),
> > which is why they are exposed.
> 
> So what do you recommend here?

Looking at 1598e38c0770, it appears the 8250 console is the 
problem.  Couldn't S390 be fenced by SERIAL_8250_CONSOLE, instead
of SERIAL_8250, which would make the 8250 driver available?

For now, just disabling the driver on S390 sounds reasonable.
-- 
Jonathan

Re: [PATCH] ptp: ocp: don't allow on S390

[Randy Dunlap]

On 8/16/21 2:41 PM, Jonathan Lemon wrote:
> On Mon, Aug 16, 2021 at 02:15:51PM -0700, Randy Dunlap wrote:
>> On 8/16/21 2:09 PM, Jonathan Lemon wrote:
>>> On Fri, Aug 13, 2021 at 01:30:26PM -0700, Randy Dunlap wrote:
>>>> There is no 8250 serial on S390. See commit 1598e38c0770.
>>>
>>> There's a 8250 serial device on the PCI card.   Its been
>>> ages since I've worked on the architecture, but does S390
>>> even support PCI?
>>
>> Yes, it does.
>>
>>>> Is this driver useful even without 8250 serial?
>>>
>>> The FB timecard has an FPGA that will internally parse the
>>> GNSS strings and correct the clock, so the PTP clock will
>>> work even without the serial devices.
>>>
>>> However, there are userspace tools which want to read the
>>> GNSS signal (for holdolver and leap second indication),
>>> which is why they are exposed.
>>
>> So what do you recommend here?
> 
> Looking at 1598e38c0770, it appears the 8250 console is the
> problem.  Couldn't S390 be fenced by SERIAL_8250_CONSOLE, instead
> of SERIAL_8250, which would make the 8250 driver available?

OK, that sounds somewhat reasonable.

> For now, just disabling the driver on S390 sounds reasonable.
> 

S390 people, how does this look to you?

This still avoids having serial 8250 console conflicting
with S390's sclp console.
(reference commit 1598e38c0770)


---
  drivers/tty/serial/8250/Kconfig |    2 +-
  1 file changed, 1 insertion(+), 1 deletion(-)

--- linux-next-20210819.orig/drivers/tty/serial/8250/Kconfig
+++ linux-next-20210819/drivers/tty/serial/8250/Kconfig
@@ -6,7 +6,6 @@
  
  config SERIAL_8250
  	tristate "8250/16550 and compatible serial support"
-	depends on !S390
  	select SERIAL_CORE
  	select SERIAL_MCTRL_GPIO if GPIOLIB
  	help
@@ -85,6 +84,7 @@ config SERIAL_8250_FINTEK
  config SERIAL_8250_CONSOLE
  	bool "Console on 8250/16550 and compatible serial port"
  	depends on SERIAL_8250=y
+	depends on !S390
  	select SERIAL_CORE_CONSOLE
  	select SERIAL_EARLYCON
  	help


-- 
~Randy

Re: [PATCH] ptp: ocp: don't allow on S390

[Christian Borntraeger]

On 20.08.21 00:58, Randy Dunlap wrote:
> On 8/16/21 2:41 PM, Jonathan Lemon wrote:
>> On Mon, Aug 16, 2021 at 02:15:51PM -0700, Randy Dunlap wrote:
>>> On 8/16/21 2:09 PM, Jonathan Lemon wrote:
>>>> On Fri, Aug 13, 2021 at 01:30:26PM -0700, Randy Dunlap wrote:
>>>>> There is no 8250 serial on S390. See commit 1598e38c0770.
>>>>
>>>> There's a 8250 serial device on the PCI card.   Its been
>>>> ages since I've worked on the architecture, but does S390
>>>> even support PCI?
>>>
>>> Yes, it does.

We do support PCI, but only a (very) limited amount of cards.
So there never will be a PCI card with 8250 on s390 and
I also doubt that we will see the "OpenCompute TimeCard"
on s390.

So in essence the original patch is ok but the patch below
would also be ok for KVM. But it results in a larger kernel
with code that will never be used. So I guess the original
patch is the better choice.

>>>
>>>>> Is this driver useful even without 8250 serial?
>>>>
>>>> The FB timecard has an FPGA that will internally parse the
>>>> GNSS strings and correct the clock, so the PTP clock will
>>>> work even without the serial devices.
>>>>
>>>> However, there are userspace tools which want to read the
>>>> GNSS signal (for holdolver and leap second indication),
>>>> which is why they are exposed.
>>>
>>> So what do you recommend here?
>>
>> Looking at 1598e38c0770, it appears the 8250 console is the
>> problem.  Couldn't S390 be fenced by SERIAL_8250_CONSOLE, instead
>> of SERIAL_8250, which would make the 8250 driver available?
> 
> OK, that sounds somewhat reasonable.
> 
>> For now, just disabling the driver on S390 sounds reasonable.
>>
> 
> S390 people, how does this look to you?
> 
> This still avoids having serial 8250 console conflicting
> with S390's sclp console.
> (reference commit 1598e38c0770)
> 
> 
> ---
>   drivers/tty/serial/8250/Kconfig |    2 +-
>   1 file changed, 1 insertion(+), 1 deletion(-)
> 
> --- linux-next-20210819.orig/drivers/tty/serial/8250/Kconfig
> +++ linux-next-20210819/drivers/tty/serial/8250/Kconfig
> @@ -6,7 +6,6 @@
> 
>   config SERIAL_8250
>       tristate "8250/16550 and compatible serial support"
> -    depends on !S390
>       select SERIAL_CORE
>       select SERIAL_MCTRL_GPIO if GPIOLIB
>       help
> @@ -85,6 +84,7 @@ config SERIAL_8250_FINTEK
>   config SERIAL_8250_CONSOLE
>       bool "Console on 8250/16550 and compatible serial port"
>       depends on SERIAL_8250=y
> +    depends on !S390
>       select SERIAL_CORE_CONSOLE
>       select SERIAL_EARLYCON
>       help
> 
> 

Re: [PATCH] ptp: ocp: don't allow on S390

[Niklas Schnelle]

On Fri, 2021-08-20 at 10:02 +0200, Christian Borntraeger wrote:
> 
> On 20.08.21 00:58, Randy Dunlap wrote:
> > On 8/16/21 2:41 PM, Jonathan Lemon wrote:
> > > On Mon, Aug 16, 2021 at 02:15:51PM -0700, Randy Dunlap wrote:
> > > > On 8/16/21 2:09 PM, Jonathan Lemon wrote:
> > > > > On Fri, Aug 13, 2021 at 01:30:26PM -0700, Randy Dunlap wrote:
> > > > > > There is no 8250 serial on S390. See commit 1598e38c0770.
> > > > > 
> > > > > There's a 8250 serial device on the PCI card.   Its been
> > > > > ages since I've worked on the architecture, but does S390
> > > > > even support PCI?
> > > > 
> > > > Yes, it does.
> 
> We do support PCI, but only a (very) limited amount of cards.
> So there never will be a PCI card with 8250 on s390 and
> I also doubt that we will see the "OpenCompute TimeCard"
> on s390.
> 
> So in essence the original patch is ok but the patch below
> would also be ok for KVM. But it results in a larger kernel
> with code that will never be used. So I guess the original
> patch is the better choice.

It looks to me like the SERIAL_8250 driver can be build as a module so
would then not increase the kernel image size or am I missing
something?

In that case I would vote for the patch below. For PCI on s390 we do
intend to, in principle, support arbitrary PCI devices and have already
seen cases where non-trivial cards that were never before tested on
s390 did "just work" once someone needed them.

While I do agree that both 8250 and the Time Card are unlikely to be
used on s390 never say never and compile testing a variety of driver
code against our PCI primitives is good for quality control.

In the end I'm okay with either.

> 
> > > > > > Is this driver useful even without 8250 serial?
> > > > > 
> > > > > The FB timecard has an FPGA that will internally parse the
> > > > > GNSS strings and correct the clock, so the PTP clock will
> > > > > work even without the serial devices.
> > > > > 
> > > > > However, there are userspace tools which want to read the
> > > > > GNSS signal (for holdolver and leap second indication),
> > > > > which is why they are exposed.
> > > > 
> > > > So what do you recommend here?
> > > 
> > > Looking at 1598e38c0770, it appears the 8250 console is the
> > > problem.  Couldn't S390 be fenced by SERIAL_8250_CONSOLE, instead
> > > of SERIAL_8250, which would make the 8250 driver available?
> > 
> > OK, that sounds somewhat reasonable.
> > 
> > > For now, just disabling the driver on S390 sounds reasonable.
> > > 
> > 
> > S390 people, how does this look to you?
> > 
> > This still avoids having serial 8250 console conflicting
> > with S390's sclp console.
> > (reference commit 1598e38c0770)
> > 
> > 
> > ---
> >   drivers/tty/serial/8250/Kconfig |    2 +-
> >   1 file changed, 1 insertion(+), 1 deletion(-)
> > 
> > --- linux-next-20210819.orig/drivers/tty/serial/8250/Kconfig
> > +++ linux-next-20210819/drivers/tty/serial/8250/Kconfig
> > @@ -6,7 +6,6 @@
> > 
> >   config SERIAL_8250
> >       tristate "8250/16550 and compatible serial support"
> > -    depends on !S390
> >       select SERIAL_CORE
> >       select SERIAL_MCTRL_GPIO if GPIOLIB
> >       help
> > @@ -85,6 +84,7 @@ config SERIAL_8250_FINTEK
> >   config SERIAL_8250_CONSOLE
> >       bool "Console on 8250/16550 and compatible serial port"
> >       depends on SERIAL_8250=y
> > +    depends on !S390
> >       select SERIAL_CORE_CONSOLE
> >       select SERIAL_EARLYCON
> >       help
> > 
> > 

Re: [PATCH] ptp: ocp: don't allow on S390

[Arnd Bergmann]

On Fri, Aug 13, 2021 at 10:30 PM Randy Dunlap <rdunlap@infradead.org> wrote:
>
> Fix kconfig warning on arch/s390/:
>
> WARNING: unmet direct dependencies detected for SERIAL_8250
>   Depends on [n]: TTY [=y] && HAS_IOMEM [=y] && !S390 [=y]
>   Selected by [m]:
>   - PTP_1588_CLOCK_OCP [=m] && PTP_1588_CLOCK [=m] && HAS_IOMEM [=y] && PCI [=y] && SPI [=y] && I2C [=m] && MTD [=m]
>
> Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
> Cc: Richard Cochran <richardcochran@gmail.com>
> Cc: Jonathan Lemon <jonathan.lemon@gmail.com>
> ---
> There is no 8250 serial on S390. See commit 1598e38c0770.
> Is this driver useful even without 8250 serial?

I think an easier way to do this would be to remove the
'select SERIAL_8250', I don't think that is actually a compile-time
dependency, just something that you normally want to enable
to make the device useful.

I would also suggest removing all the 'imply' statements, they
usually don't do what the original author intended anyway.
If there is a compile-time dependency with those drivers,
it should be 'depends on', otherwise they can normally be
left out.

       Arnd

Re: [PATCH] ptp: ocp: don't allow on S390

[Richard Cochran]

On Fri, Aug 20, 2021 at 12:45:42PM +0200, Arnd Bergmann wrote:

> I would also suggest removing all the 'imply' statements, they
> usually don't do what the original author intended anyway.
> If there is a compile-time dependency with those drivers,
> it should be 'depends on', otherwise they can normally be
> left out.

+1

Re: [PATCH] ptp: ocp: don't allow on S390

[Randy Dunlap]

On 8/20/21 8:31 AM, Richard Cochran wrote:
> On Fri, Aug 20, 2021 at 12:45:42PM +0200, Arnd Bergmann wrote:
> 
>> I would also suggest removing all the 'imply' statements, they
>> usually don't do what the original author intended anyway.
>> If there is a compile-time dependency with those drivers,
>> it should be 'depends on', otherwise they can normally be
>> left out.
> 
> +1

Hi,

Removing the "imply" statements is simple enough and the driver
still builds cleanly without them, so Yes, they aren't needed here.

Removing the SPI dependency is also clean.

The driver does use I2C, MTD, and SERIAL_8250 interfaces, so they
can't be removed without some other driver changes, like using
#ifdef/#endif (or #if IS_ENABLED()) blocks and some function stubs.


-- 
~Randy

Re: [PATCH] ptp: ocp: don't allow on S390

[Arnd Bergmann]

On Tue, Aug 24, 2021 at 11:48 PM Randy Dunlap <rdunlap@infradead.org> wrote:
>
> On 8/20/21 8:31 AM, Richard Cochran wrote:
> > On Fri, Aug 20, 2021 at 12:45:42PM +0200, Arnd Bergmann wrote:
> >
> >> I would also suggest removing all the 'imply' statements, they
> >> usually don't do what the original author intended anyway.
> >> If there is a compile-time dependency with those drivers,
> >> it should be 'depends on', otherwise they can normally be
> >> left out.
> >
> > +1
>
> Hi,
>
> Removing the "imply" statements is simple enough and the driver
> still builds cleanly without them, so Yes, they aren't needed here.
>
> Removing the SPI dependency is also clean.
>
> The driver does use I2C, MTD, and SERIAL_8250 interfaces, so they
> can't be removed without some other driver changes, like using
> #ifdef/#endif (or #if IS_ENABLED()) blocks and some function stubs.

If the SERIAL_8250 dependency is actually required, then using
'depends on' for this is probably better than an IS_ENABLED() check.
The 'select' is definitely misplaced here, that doesn't even work when
the dependencies fo 8250 itself are not met, and it does force-enable
the entire TTY subsystem.

      Arnd


        Arnd

Re: [PATCH] ptp: ocp: don't allow on S390

[Jonathan Lemon]

On Wed, Aug 25, 2021 at 12:55:25PM +0200, Arnd Bergmann wrote:
> On Tue, Aug 24, 2021 at 11:48 PM Randy Dunlap <rdunlap@infradead.org> wrote:
> >
> > On 8/20/21 8:31 AM, Richard Cochran wrote:
> > > On Fri, Aug 20, 2021 at 12:45:42PM +0200, Arnd Bergmann wrote:
> > >
> > >> I would also suggest removing all the 'imply' statements, they
> > >> usually don't do what the original author intended anyway.
> > >> If there is a compile-time dependency with those drivers,
> > >> it should be 'depends on', otherwise they can normally be
> > >> left out.
> > >
> > > +1
> >
> > Hi,
> >
> > Removing the "imply" statements is simple enough and the driver
> > still builds cleanly without them, so Yes, they aren't needed here.
> >
> > Removing the SPI dependency is also clean.
> >
> > The driver does use I2C, MTD, and SERIAL_8250 interfaces, so they
> > can't be removed without some other driver changes, like using
> > #ifdef/#endif (or #if IS_ENABLED()) blocks and some function stubs.
> 
> If the SERIAL_8250 dependency is actually required, then using
> 'depends on' for this is probably better than an IS_ENABLED() check.
> The 'select' is definitely misplaced here, that doesn't even work when
> the dependencies fo 8250 itself are not met, and it does force-enable
> the entire TTY subsystem.

So, something like the following (untested) patch?
I admit to not fully understanding all the nuances around Kconfig.
-- 
Jonathan

diff --git a/drivers/ptp/Kconfig b/drivers/ptp/Kconfig
index 32660dc11354..c3372efd1bb7 100644
--- a/drivers/ptp/Kconfig
+++ b/drivers/ptp/Kconfig
@@ -171,15 +171,10 @@ config PTP_1588_CLOCK_OCP
        tristate "OpenCompute TimeCard as PTP clock"
        depends on PTP_1588_CLOCK
        depends on HAS_IOMEM && PCI
-       depends on SPI && I2C && MTD
+       depends on I2C && MTD
+       depends on SERIAL_8250
        depends on !S390
-       imply SPI_MEM
-       imply SPI_XILINX
-       imply MTD_SPI_NOR
-       imply I2C_XILINX
-       select SERIAL_8250
        select NET_DEVLINK
-
        default n
        help
          This driver adds support for an OpenCompute time card.

Re: [PATCH] ptp: ocp: don't allow on S390

[Randy Dunlap]

On 8/25/21 10:08 AM, Jonathan Lemon wrote:
> On Wed, Aug 25, 2021 at 12:55:25PM +0200, Arnd Bergmann wrote:
>> On Tue, Aug 24, 2021 at 11:48 PM Randy Dunlap <rdunlap@infradead.org> wrote:
>>>
>>> On 8/20/21 8:31 AM, Richard Cochran wrote:
>>>> On Fri, Aug 20, 2021 at 12:45:42PM +0200, Arnd Bergmann wrote:
>>>>
>>>>> I would also suggest removing all the 'imply' statements, they
>>>>> usually don't do what the original author intended anyway.
>>>>> If there is a compile-time dependency with those drivers,
>>>>> it should be 'depends on', otherwise they can normally be
>>>>> left out.
>>>>
>>>> +1
>>>
>>> Hi,
>>>
>>> Removing the "imply" statements is simple enough and the driver
>>> still builds cleanly without them, so Yes, they aren't needed here.
>>>
>>> Removing the SPI dependency is also clean.
>>>
>>> The driver does use I2C, MTD, and SERIAL_8250 interfaces, so they
>>> can't be removed without some other driver changes, like using
>>> #ifdef/#endif (or #if IS_ENABLED()) blocks and some function stubs.
>>
>> If the SERIAL_8250 dependency is actually required, then using
>> 'depends on' for this is probably better than an IS_ENABLED() check.
>> The 'select' is definitely misplaced here, that doesn't even work when
>> the dependencies fo 8250 itself are not met, and it does force-enable
>> the entire TTY subsystem.
> 
> So, something like the following (untested) patch?
> I admit to not fully understanding all the nuances around Kconfig.

Hi,

You can also remove the "select NET_DEVLINK". The driver builds fine
without it. And please drop the "default n" while at it.

After that, your patch will match my (tested) patch.  :)

thanks.

-- 
~Randy

Re: [PATCH] ptp: ocp: don't allow on S390

[Arnd Bergmann]

On Wed, Aug 25, 2021 at 7:29 PM Randy Dunlap <rdunlap@infradead.org> wrote:
> On 8/25/21 10:08 AM, Jonathan Lemon wrote:
> > So, something like the following (untested) patch?
> > I admit to not fully understanding all the nuances around Kconfig.
>
> You can also remove the "select NET_DEVLINK". The driver builds fine
> without it. And please drop the "default n" while at it.
>
> After that, your patch will match my (tested) patch.  :)

That version sounds good to me.

       Arnd

Re: [PATCH] ptp: ocp: don't allow on S390

[Jonathan Lemon]

On Wed, Aug 25, 2021 at 10:29:51AM -0700, Randy Dunlap wrote:
> On 8/25/21 10:08 AM, Jonathan Lemon wrote:
> > On Wed, Aug 25, 2021 at 12:55:25PM +0200, Arnd Bergmann wrote:
> > > On Tue, Aug 24, 2021 at 11:48 PM Randy Dunlap <rdunlap@infradead.org> wrote:
> > > > 
> > > > On 8/20/21 8:31 AM, Richard Cochran wrote:
> > > > > On Fri, Aug 20, 2021 at 12:45:42PM +0200, Arnd Bergmann wrote:
> > > > > 
> > > > > > I would also suggest removing all the 'imply' statements, they
> > > > > > usually don't do what the original author intended anyway.
> > > > > > If there is a compile-time dependency with those drivers,
> > > > > > it should be 'depends on', otherwise they can normally be
> > > > > > left out.
> > > > > 
> > > > > +1
> > > > 
> > > > Hi,
> > > > 
> > > > Removing the "imply" statements is simple enough and the driver
> > > > still builds cleanly without them, so Yes, they aren't needed here.
> > > > 
> > > > Removing the SPI dependency is also clean.
> > > > 
> > > > The driver does use I2C, MTD, and SERIAL_8250 interfaces, so they
> > > > can't be removed without some other driver changes, like using
> > > > #ifdef/#endif (or #if IS_ENABLED()) blocks and some function stubs.
> > > 
> > > If the SERIAL_8250 dependency is actually required, then using
> > > 'depends on' for this is probably better than an IS_ENABLED() check.
> > > The 'select' is definitely misplaced here, that doesn't even work when
> > > the dependencies fo 8250 itself are not met, and it does force-enable
> > > the entire TTY subsystem.
> > 
> > So, something like the following (untested) patch?
> > I admit to not fully understanding all the nuances around Kconfig.
> 
> Hi,
> 
> You can also remove the "select NET_DEVLINK". The driver builds fine
> without it. And please drop the "default n" while at it.

I had to add this one because devlink is a dependency and the kbuild
robot generated a config without it.

The 'imply' statements were added because while the driver builds
without them, the resources don't show up unless the platform
modules are also present.  This was really confusing users, since
they selected the OCP driver and then were not able to use the 
flash since the XILINX modules had not been selected.

Is there a better way of specifying these type of dependencies?
-- 
Jonathan

Re: [PATCH] ptp: ocp: don't allow on S390

[Randy Dunlap]

On 8/25/21 1:40 PM, Jonathan Lemon wrote:
> On Wed, Aug 25, 2021 at 10:29:51AM -0700, Randy Dunlap wrote:
>> On 8/25/21 10:08 AM, Jonathan Lemon wrote:
>>> On Wed, Aug 25, 2021 at 12:55:25PM +0200, Arnd Bergmann wrote:
>>>> On Tue, Aug 24, 2021 at 11:48 PM Randy Dunlap <rdunlap@infradead.org> wrote:
>>>>>
>>>>> On 8/20/21 8:31 AM, Richard Cochran wrote:
>>>>>> On Fri, Aug 20, 2021 at 12:45:42PM +0200, Arnd Bergmann wrote:
>>>>>>
>>>>>>> I would also suggest removing all the 'imply' statements, they
>>>>>>> usually don't do what the original author intended anyway.
>>>>>>> If there is a compile-time dependency with those drivers,
>>>>>>> it should be 'depends on', otherwise they can normally be
>>>>>>> left out.
>>>>>>
>>>>>> +1
>>>>>
>>>>> Hi,
>>>>>
>>>>> Removing the "imply" statements is simple enough and the driver
>>>>> still builds cleanly without them, so Yes, they aren't needed here.
>>>>>
>>>>> Removing the SPI dependency is also clean.
>>>>>
>>>>> The driver does use I2C, MTD, and SERIAL_8250 interfaces, so they
>>>>> can't be removed without some other driver changes, like using
>>>>> #ifdef/#endif (or #if IS_ENABLED()) blocks and some function stubs.
>>>>
>>>> If the SERIAL_8250 dependency is actually required, then using
>>>> 'depends on' for this is probably better than an IS_ENABLED() check.
>>>> The 'select' is definitely misplaced here, that doesn't even work when
>>>> the dependencies fo 8250 itself are not met, and it does force-enable
>>>> the entire TTY subsystem.
>>>
>>> So, something like the following (untested) patch?
>>> I admit to not fully understanding all the nuances around Kconfig.
>>
>> Hi,
>>
>> You can also remove the "select NET_DEVLINK". The driver builds fine
>> without it. And please drop the "default n" while at it.
> 
> I had to add this one because devlink is a dependency and the kbuild
> robot generated a config without it.

What kind of dependency is devlink?
The driver builds without NET_DEVLINK.


> The 'imply' statements were added because while the driver builds
> without them, the resources don't show up unless the platform
> modules are also present.  This was really confusing users, since
> they selected the OCP driver and then were not able to use the
> flash since the XILINX modules had not been selected.
> 
> Is there a better way of specifying these type of dependencies?

Documentation/  and/or one can add comments/docs in the Kconfig help
section.


-- 
~Randy

Re: [PATCH] ptp: ocp: don't allow on S390

[Jonathan Lemon]

On Wed, Aug 25, 2021 at 01:45:57PM -0700, Randy Dunlap wrote:
> On 8/25/21 1:40 PM, Jonathan Lemon wrote:
> > On Wed, Aug 25, 2021 at 10:29:51AM -0700, Randy Dunlap wrote:
> > > On 8/25/21 10:08 AM, Jonathan Lemon wrote:
> > > > On Wed, Aug 25, 2021 at 12:55:25PM +0200, Arnd Bergmann wrote:
> > > > > On Tue, Aug 24, 2021 at 11:48 PM Randy Dunlap <rdunlap@infradead.org> wrote:
> > > > > > 
> > > > > > On 8/20/21 8:31 AM, Richard Cochran wrote:
> > > > > > > On Fri, Aug 20, 2021 at 12:45:42PM +0200, Arnd Bergmann wrote:
> > > > > > > 
> > > > > > > > I would also suggest removing all the 'imply' statements, they
> > > > > > > > usually don't do what the original author intended anyway.
> > > > > > > > If there is a compile-time dependency with those drivers,
> > > > > > > > it should be 'depends on', otherwise they can normally be
> > > > > > > > left out.
> > > > > > > 
> > > > > > > +1
> > > > > > 
> > > > > > Hi,
> > > > > > 
> > > > > > Removing the "imply" statements is simple enough and the driver
> > > > > > still builds cleanly without them, so Yes, they aren't needed here.
> > > > > > 
> > > > > > Removing the SPI dependency is also clean.
> > > > > > 
> > > > > > The driver does use I2C, MTD, and SERIAL_8250 interfaces, so they
> > > > > > can't be removed without some other driver changes, like using
> > > > > > #ifdef/#endif (or #if IS_ENABLED()) blocks and some function stubs.
> > > > > 
> > > > > If the SERIAL_8250 dependency is actually required, then using
> > > > > 'depends on' for this is probably better than an IS_ENABLED() check.
> > > > > The 'select' is definitely misplaced here, that doesn't even work when
> > > > > the dependencies fo 8250 itself are not met, and it does force-enable
> > > > > the entire TTY subsystem.
> > > > 
> > > > So, something like the following (untested) patch?
> > > > I admit to not fully understanding all the nuances around Kconfig.
> > > 
> > > Hi,
> > > 
> > > You can also remove the "select NET_DEVLINK". The driver builds fine
> > > without it. And please drop the "default n" while at it.
> > 
> > I had to add this one because devlink is a dependency and the kbuild
> > robot generated a config without it.
> 
> What kind of dependency is devlink?
> The driver builds without NET_DEVLINK.

It really doesn't.  Odds are one of the network drivers is also
selecting this as well, so it is hidden.
-- 
Jonathan

Re: [PATCH] ptp: ocp: don't allow on S390

[Randy Dunlap]

On 8/25/21 2:14 PM, Jonathan Lemon wrote:
> On Wed, Aug 25, 2021 at 01:45:57PM -0700, Randy Dunlap wrote:
>> On 8/25/21 1:40 PM, Jonathan Lemon wrote:
>>> On Wed, Aug 25, 2021 at 10:29:51AM -0700, Randy Dunlap wrote:
>>>> On 8/25/21 10:08 AM, Jonathan Lemon wrote:
>>>>> On Wed, Aug 25, 2021 at 12:55:25PM +0200, Arnd Bergmann wrote:
>>>>>> On Tue, Aug 24, 2021 at 11:48 PM Randy Dunlap <rdunlap@infradead.org> wrote:
>>>>>>>
>>>>>>> On 8/20/21 8:31 AM, Richard Cochran wrote:
>>>>>>>> On Fri, Aug 20, 2021 at 12:45:42PM +0200, Arnd Bergmann wrote:
>>>>>>>>
>>>>>>>>> I would also suggest removing all the 'imply' statements, they
>>>>>>>>> usually don't do what the original author intended anyway.
>>>>>>>>> If there is a compile-time dependency with those drivers,
>>>>>>>>> it should be 'depends on', otherwise they can normally be
>>>>>>>>> left out.
>>>>>>>>
>>>>>>>> +1
>>>>>>>
>>>>>>> Hi,
>>>>>>>
>>>>>>> Removing the "imply" statements is simple enough and the driver
>>>>>>> still builds cleanly without them, so Yes, they aren't needed here.
>>>>>>>
>>>>>>> Removing the SPI dependency is also clean.
>>>>>>>
>>>>>>> The driver does use I2C, MTD, and SERIAL_8250 interfaces, so they
>>>>>>> can't be removed without some other driver changes, like using
>>>>>>> #ifdef/#endif (or #if IS_ENABLED()) blocks and some function stubs.
>>>>>>
>>>>>> If the SERIAL_8250 dependency is actually required, then using
>>>>>> 'depends on' for this is probably better than an IS_ENABLED() check.
>>>>>> The 'select' is definitely misplaced here, that doesn't even work when
>>>>>> the dependencies fo 8250 itself are not met, and it does force-enable
>>>>>> the entire TTY subsystem.
>>>>>
>>>>> So, something like the following (untested) patch?
>>>>> I admit to not fully understanding all the nuances around Kconfig.
>>>>
>>>> Hi,
>>>>
>>>> You can also remove the "select NET_DEVLINK". The driver builds fine
>>>> without it. And please drop the "default n" while at it.
>>>
>>> I had to add this one because devlink is a dependency and the kbuild
>>> robot generated a config without it.
>>
>> What kind of dependency is devlink?
>> The driver builds without NET_DEVLINK.
> 
> It really doesn't.  Odds are one of the network drivers is also
> selecting this as well, so it is hidden.
> 

OK, my mistake. Thanks.

-- 
~Randy