Re: [RESEND PATCH -net] cpsw/netcp: cpts depends on posix_timers

[Nicolas Pitre]

On Mon, 13 Mar 2017, Arnd Bergmann wrote:

> With posix timers having become optional, we get a build error with
> the cpts time sync option of the CPSW driver:
> 
> drivers/net/ethernet/ti/cpts.c: In function 'cpts_find_ts':
> drivers/net/ethernet/ti/cpts.c:291:23: error: implicit declaration of function 'ptp_classify_raw';did you mean 'ptp_classifier_init'? [-Werror=implicit-function-declaration]
> 
> It really makes no sense to build this driver if we can't use PTP,
> so it's better to go back to 'select PTP_1588_CLOCK' but instead
> add a dependency on POSIX_TIMERS. Adding 'depends on PTP_1588_CLOCK'
> might also work, but has the risk of circular dependencies when
> mixed with other drivers using 'imply'.

Could you elaborate on that risk please?


> Fixes: baa73d9e478f ("posix-timers: Make them configurable")
> Cc: Nicolas Pitre <nicolas.pitre@xxxxxxxxxx>
> Cc: stable@xxxxxxxxxxxxxxx
> Signed-off-by: Arnd Bergmann <arnd@xxxxxxxx>
> ---
> Originally submitted on Dec 16, but not applied after I missed a
> reply from Nico. I confirmed that this is still needed for v4.10
> and v4.11-rc2 and am resending it without changes.
> ---
>  drivers/net/ethernet/ti/Kconfig | 3 ++-
>  1 file changed, 2 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/net/ethernet/ti/Kconfig b/drivers/net/ethernet/ti/Kconfig
> index d42257fbe9d9..c114efcd1575 100644
> --- a/drivers/net/ethernet/ti/Kconfig
> +++ b/drivers/net/ethernet/ti/Kconfig
> @@ -76,7 +76,8 @@ config TI_CPSW
>  config TI_CPTS_ENABLE
>  	bool "TI Common Platform Time Sync (CPTS) Support"
>  	depends on TI_CPSW || TI_KEYSTONE_NETCP
> -	imply PTP_1588_CLOCK
> +	depends on POSIX_TIMERS
> +	select 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.
> -- 
> 2.9.0
> 
>