If CONFIG_PTP_1588_CLOCK=m and CONFIG_SFC_SIENA=y, the siena driver will fail to link:

drivers/net/ethernet/sfc/siena/ptp.o: In function `efx_ptp_remove_channel':
ptp.c:(.text+0xa28): undefined reference to `ptp_clock_unregister'
drivers/net/ethernet/sfc/siena/ptp.o: In function `efx_ptp_probe_channel':
ptp.c:(.text+0x13a0): undefined reference to `ptp_clock_register'
ptp.c:(.text+0x1470): undefined reference to `ptp_clock_unregister'
drivers/net/ethernet/sfc/siena/ptp.o: In function `efx_ptp_pps_worker':
ptp.c:(.text+0x1d29): undefined reference to `ptp_clock_event'
drivers/net/ethernet/sfc/siena/ptp.o: In function `efx_siena_ptp_get_ts_info':
ptp.c:(.text+0x301b): undefined reference to `ptp_clock_index'

To fix this build error, make SFC_SIENA depends on PTP_1588_CLOCK.

Reported-by: Hulk Robot <hulkci@huawei.com>
Fixes: d48523cb88e0("sfc: Copy shared files needed for Siena (part 2)")
Signed-off-by: Ren Zhijie <renzhijie2@huawei.com>
---
 drivers/net/ethernet/sfc/siena/Kconfig | 1 +
 1 file changed, 1 insertion(+)

diff --git a/drivers/net/ethernet/sfc/siena/Kconfig b/drivers/net/ethernet/sfc/siena/Kconfig
index 3d52aee50d5a..3675233e963a 100644
--- a/drivers/net/ethernet/sfc/siena/Kconfig
+++ b/drivers/net/ethernet/sfc/siena/Kconfig
@@ -2,6 +2,7 @@
 config SFC_SIENA
 	tristate "Solarflare SFC9000 support"
 	depends on PCI
+	depends on PTP_1588_CLOCK
 	select MDIO
 	select CRC32
 	help
-- 
2.17.1

Hello:

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

On Fri, 13 May 2022 09:27:21 +0800 you wrote:
> If CONFIG_PTP_1588_CLOCK=m and CONFIG_SFC_SIENA=y, the siena driver will fail to link:
> 
> drivers/net/ethernet/sfc/siena/ptp.o: In function `efx_ptp_remove_channel':
> ptp.c:(.text+0xa28): undefined reference to `ptp_clock_unregister'
> drivers/net/ethernet/sfc/siena/ptp.o: In function `efx_ptp_probe_channel':
> ptp.c:(.text+0x13a0): undefined reference to `ptp_clock_register'
> ptp.c:(.text+0x1470): undefined reference to `ptp_clock_unregister'
> drivers/net/ethernet/sfc/siena/ptp.o: In function `efx_ptp_pps_worker':
> ptp.c:(.text+0x1d29): undefined reference to `ptp_clock_event'
> drivers/net/ethernet/sfc/siena/ptp.o: In function `efx_siena_ptp_get_ts_info':
> ptp.c:(.text+0x301b): undefined reference to `ptp_clock_index'
> 
> [...]

Here is the summary with links:
  - [-next] sfc: siena: Fix Kconfig dependencies
    https://git.kernel.org/netdev/net-next/c/f9a210c72d70

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

Nit: the subject should have net-next in stead of -next.

On Fri, May 13, 2022 at 09:27:21AM +0800, Ren Zhijie wrote:
> If CONFIG_PTP_1588_CLOCK=m and CONFIG_SFC_SIENA=y, the siena driver will fail to link:
> 
> drivers/net/ethernet/sfc/siena/ptp.o: In function `efx_ptp_remove_channel':
> ptp.c:(.text+0xa28): undefined reference to `ptp_clock_unregister'
> drivers/net/ethernet/sfc/siena/ptp.o: In function `efx_ptp_probe_channel':
> ptp.c:(.text+0x13a0): undefined reference to `ptp_clock_register'
> ptp.c:(.text+0x1470): undefined reference to `ptp_clock_unregister'
> drivers/net/ethernet/sfc/siena/ptp.o: In function `efx_ptp_pps_worker':
> ptp.c:(.text+0x1d29): undefined reference to `ptp_clock_event'
> drivers/net/ethernet/sfc/siena/ptp.o: In function `efx_siena_ptp_get_ts_info':
> ptp.c:(.text+0x301b): undefined reference to `ptp_clock_index'
> 
> To fix this build error, make SFC_SIENA depends on PTP_1588_CLOCK.
> 
> Reported-by: Hulk Robot <hulkci@huawei.com>
> Fixes: d48523cb88e0("sfc: Copy shared files needed for Siena (part 2)")
> Signed-off-by: Ren Zhijie <renzhijie2@huawei.com>

Acked-by: Martin Habets <habetsm.xilinx@gmail.com>

> ---
>  drivers/net/ethernet/sfc/siena/Kconfig | 1 +
>  1 file changed, 1 insertion(+)
> 
> diff --git a/drivers/net/ethernet/sfc/siena/Kconfig b/drivers/net/ethernet/sfc/siena/Kconfig
> index 3d52aee50d5a..3675233e963a 100644
> --- a/drivers/net/ethernet/sfc/siena/Kconfig
> +++ b/drivers/net/ethernet/sfc/siena/Kconfig
> @@ -2,6 +2,7 @@
>  config SFC_SIENA
>  	tristate "Solarflare SFC9000 support"
>  	depends on PCI
> +	depends on PTP_1588_CLOCK
>  	select MDIO
>  	select CRC32
>  	help
> -- 
> 2.17.1