[RESEND,-net] cpsw/netcp: work around reverse cpts dependency

The dependency is reversed: cpsw and netcp call into cpts,
but cpts depends on the other two in Kconfig. This can lead
to cpts being a loadable module and its callers built-in:

drivers/net/ethernet/ti/cpsw.o: In function `cpsw_remove':
cpsw.c:(.text.cpsw_remove+0xd0): undefined reference to `cpts_release'
drivers/net/ethernet/ti/cpsw.o: In function `cpsw_rx_handler':
cpsw.c:(.text.cpsw_rx_handler+0x2dc): undefined reference to `cpts_rx_timestamp'
drivers/net/ethernet/ti/cpsw.o: In function `cpsw_tx_handler':
cpsw.c:(.text.cpsw_tx_handler+0x7c): undefined reference to `cpts_tx_timestamp'
drivers/net/ethernet/ti/cpsw.o: In function `cpsw_ndo_stop':

As a workaround, I'm introducing another Kconfig symbol to
control the compilation of cpts, while making the actual
module controlled by a silent symbol that is =y when necessary.

Fixes: 6246168b4a38 ("net: ethernet: ti: netcp: add support of cpts")
Signed-off-by: Arnd Bergmann <arnd@arndb.de>
Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
---
Originally submitted on Dec 16, still needed for v4.10 and v4.11-rc2
---
 drivers/net/ethernet/ti/Kconfig | 10 ++++++++--
 1 file changed, 8 insertions(+), 2 deletions(-)

From: Arnd Bergmann <arnd@arndb.de>
Date: Mon, 13 Mar 2017 17:59:04 +0100

> The dependency is reversed: cpsw and netcp call into cpts,
> but cpts depends on the other two in Kconfig. This can lead
> to cpts being a loadable module and its callers built-in:
> 
> drivers/net/ethernet/ti/cpsw.o: In function `cpsw_remove':
> cpsw.c:(.text.cpsw_remove+0xd0): undefined reference to `cpts_release'
> drivers/net/ethernet/ti/cpsw.o: In function `cpsw_rx_handler':
> cpsw.c:(.text.cpsw_rx_handler+0x2dc): undefined reference to `cpts_rx_timestamp'
> drivers/net/ethernet/ti/cpsw.o: In function `cpsw_tx_handler':
> cpsw.c:(.text.cpsw_tx_handler+0x7c): undefined reference to `cpts_tx_timestamp'
> drivers/net/ethernet/ti/cpsw.o: In function `cpsw_ndo_stop':
> 
> As a workaround, I'm introducing another Kconfig symbol to
> control the compilation of cpts, while making the actual
> module controlled by a silent symbol that is =y when necessary.
> 
> Fixes: 6246168b4a38 ("net: ethernet: ti: netcp: add support of cpts")
> Signed-off-by: Arnd Bergmann <arnd@arndb.de>
> Reviewed-by: Grygorii Strashko <grygorii.strashko@ti.com>
> ---
> Originally submitted on Dec 16, still needed for v4.10 and v4.11-rc2

I'm fine with this change, but please keep the user visible Kconfig
symbol name the same, use the new name for the internal one.

I know that this means you have to make more changes elsewhere in
order to accomplish this.

On Fri, Mar 17, 2017 at 4:13 AM, David Miller <davem@davemloft.net> wrote:
>
> I'm fine with this change, but please keep the user visible Kconfig
> symbol name the same, use the new name for the internal one.

Yes, makes snese.

> I know that this means you have to make more changes elsewhere in
> order to accomplish this.

It turned out to require just one extra change line, as the other references
work either way (they use IS_ENABLED()). I'm running a little more build
tests and will then submit the new version.

     Arnd