[PATCH 4.19 18/56] hv: utils: add PTP_1588_CLOCK to Kconfig to fix build

[PATCH 4.19 18/56] hv: utils: add PTP_1588_CLOCK to Kconfig to fix build

[Greg Kroah-Hartman]

From: Randy Dunlap <rdunlap@infradead.org>

[ Upstream commit 1dc2f2b81a6a9895da59f3915760f6c0c3074492 ]

The hyperv utilities use PTP clock interfaces and should depend a
a kconfig symbol such that they will be built as a loadable module or
builtin so that linker errors do not happen.

Prevents these build errors:

ld: drivers/hv/hv_util.o: in function `hv_timesync_deinit':
hv_util.c:(.text+0x37d): undefined reference to `ptp_clock_unregister'
ld: drivers/hv/hv_util.o: in function `hv_timesync_init':
hv_util.c:(.text+0x738): undefined reference to `ptp_clock_register'

Fixes: 3716a49a81ba ("hv_utils: implement Hyper-V PTP source")
Signed-off-by: Randy Dunlap <rdunlap@infradead.org>
Reported-by: kernel test robot <lkp@intel.com>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: "K. Y. Srinivasan" <kys@microsoft.com>
Cc: Haiyang Zhang <haiyangz@microsoft.com>
Cc: Stephen Hemminger <sthemmin@microsoft.com>
Cc: Wei Liu <wei.liu@kernel.org>
Cc: Dexuan Cui <decui@microsoft.com>
Cc: linux-hyperv@vger.kernel.org
Cc: Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Reviewed-by: Michael Kelley <mikelley@microsoft.com>
Link: https://lore.kernel.org/r/20211126023316.25184-1-rdunlap@infradead.org
Signed-off-by: Wei Liu <wei.liu@kernel.org>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
 drivers/hv/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/hv/Kconfig b/drivers/hv/Kconfig
index 1c1a2514d6f31..b1c93441900ad 100644
--- a/drivers/hv/Kconfig
+++ b/drivers/hv/Kconfig
@@ -16,6 +16,7 @@ config HYPERV_TSCPAGE
 config HYPERV_UTILS
 	tristate "Microsoft Hyper-V Utilities driver"
 	depends on HYPERV && CONNECTOR && NLS
+	depends on PTP_1588_CLOCK_OPTIONAL
 	help
 	  Select this option to enable the Hyper-V Utilities.
 
-- 
2.33.0

Re: [PATCH 4.19 18/56] hv: utils: add PTP_1588_CLOCK to Kconfig to fix build

[Pavel Machek]

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Hi!

> From: Randy Dunlap <rdunlap@infradead.org>
> 
> [ Upstream commit 1dc2f2b81a6a9895da59f3915760f6c0c3074492 ]
> 
> The hyperv utilities use PTP clock interfaces and should depend a
> a kconfig symbol such that they will be built as a loadable module or
> builtin so that linker errors do not happen.
> 
> Prevents these build errors:
> 
> ld: drivers/hv/hv_util.o: in function `hv_timesync_deinit':
> hv_util.c:(.text+0x37d): undefined reference to `ptp_clock_unregister'
> ld: drivers/hv/hv_util.o: in function `hv_timesync_init':
> hv_util.c:(.text+0x738): undefined reference to `ptp_clock_register'

This is bad idea for 4.19:

> +++ b/drivers/hv/Kconfig
> @@ -16,6 +16,7 @@ config HYPERV_TSCPAGE
>  config HYPERV_UTILS
>  	tristate "Microsoft Hyper-V Utilities driver"
>  	depends on HYPERV && CONNECTOR && NLS
> +	depends on PTP_1588_CLOCK_OPTIONAL
>  	help
>  	  Select this option to enable the Hyper-V Utilities.

grep -ri PTP_1588_CLOCK_OPTIONAL .

Results in no result in 4.19. So this will break hyperv. No results in
5.10, either, so it is bad idea there, too.

								Pavel
-- 
http://www.livejournal.com/~pavelmachek

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Re: [PATCH 4.19 18/56] hv: utils: add PTP_1588_CLOCK to Kconfig to fix build

[Arnd Bergmann]

On Mon, Dec 20, 2021 at 9:31 PM Pavel Machek <pavel@ucw.cz> wrote:
> > From: Randy Dunlap <rdunlap@infradead.org>
> >
> > [ Upstream commit 1dc2f2b81a6a9895da59f3915760f6c0c3074492 ]
> >
> > The hyperv utilities use PTP clock interfaces and should depend a
> > a kconfig symbol such that they will be built as a loadable module or
> > builtin so that linker errors do not happen.
> >
> > Prevents these build errors:
> >
> > ld: drivers/hv/hv_util.o: in function `hv_timesync_deinit':
> > hv_util.c:(.text+0x37d): undefined reference to `ptp_clock_unregister'
> > ld: drivers/hv/hv_util.o: in function `hv_timesync_init':
> > hv_util.c:(.text+0x738): undefined reference to `ptp_clock_register'
>
> This is bad idea for 4.19:
>
> > +++ b/drivers/hv/Kconfig
> > @@ -16,6 +16,7 @@ config HYPERV_TSCPAGE
> >  config HYPERV_UTILS
> >       tristate "Microsoft Hyper-V Utilities driver"
> >       depends on HYPERV && CONNECTOR && NLS
> > +     depends on PTP_1588_CLOCK_OPTIONAL
> >       help
> >         Select this option to enable the Hyper-V Utilities.
>
> grep -ri PTP_1588_CLOCK_OPTIONAL .
>
> Results in no result in 4.19. So this will break hyperv. No results in
> 5.10, either, so it is bad idea there, too.

Right, this doesn't work, but the bug does exist anyway, and could be
fixed by listing the dependency explicitly as

           depends on PTP_1588_CLOCK || PTP_1588_CLOCK=n

The PTP_1588_CLOCK_OPTIONAL was added as a shortcut to
avoid the odd Kconfig syntax that most developers struggle with understanding
at first.

         Arnd

Re: [PATCH 4.19 18/56] hv: utils: add PTP_1588_CLOCK to Kconfig to fix build

[Greg Kroah-Hartman]

On Mon, Dec 20, 2021 at 09:31:36PM +0100, Pavel Machek wrote:
> Hi!
> 
> > From: Randy Dunlap <rdunlap@infradead.org>
> > 
> > [ Upstream commit 1dc2f2b81a6a9895da59f3915760f6c0c3074492 ]
> > 
> > The hyperv utilities use PTP clock interfaces and should depend a
> > a kconfig symbol such that they will be built as a loadable module or
> > builtin so that linker errors do not happen.
> > 
> > Prevents these build errors:
> > 
> > ld: drivers/hv/hv_util.o: in function `hv_timesync_deinit':
> > hv_util.c:(.text+0x37d): undefined reference to `ptp_clock_unregister'
> > ld: drivers/hv/hv_util.o: in function `hv_timesync_init':
> > hv_util.c:(.text+0x738): undefined reference to `ptp_clock_register'
> 
> This is bad idea for 4.19:
> 
> > +++ b/drivers/hv/Kconfig
> > @@ -16,6 +16,7 @@ config HYPERV_TSCPAGE
> >  config HYPERV_UTILS
> >  	tristate "Microsoft Hyper-V Utilities driver"
> >  	depends on HYPERV && CONNECTOR && NLS
> > +	depends on PTP_1588_CLOCK_OPTIONAL
> >  	help
> >  	  Select this option to enable the Hyper-V Utilities.
> 
> grep -ri PTP_1588_CLOCK_OPTIONAL .
> 
> Results in no result in 4.19. So this will break hyperv. No results in
> 5.10, either, so it is bad idea there, too.

Thanks, I will go delete it from all queues.

greg k-h