Re: [PATCH net v3] net: ethernet: ti: fix build and remove TI_CPTS_MOD workaround

[Grygorii Strashko]

On 08/05/2020 13:10, Arnd Bergmann wrote:
> On Fri, May 8, 2020 at 11:59 AM Grygorii Strashko
> <grygorii.strashko@xxxxxx> wrote:
> > From: Clay McClure <clay@xxxxxxxxxxx>
> >
> > My recent commit b6d49cab44b5 ("net: Make PTP-specific drivers depend on
> > PTP_1588_CLOCK") exposes a missing dependency in defconfigs that select
> > TI_CPTS without selecting PTP_1588_CLOCK, leading to linker errors of the
> > form:
> >
> > drivers/net/ethernet/ti/cpsw.o: in function `cpsw_ndo_stop':
> > cpsw.c:(.text+0x680): undefined reference to `cpts_unregister'
> >   ...
> >
> > That's because TI_CPTS_MOD (which is the symbol gating the _compilation_ of
> > cpts.c) now depends on PTP_1588_CLOCK, and so is not enabled in these
> > configurations, but TI_CPTS (which is the symbol gating _calls_ to the cpts
> > functions) _is_ enabled. So we end up compiling calls to functions that
> > don't exist, resulting in the linker errors.
> >
> > This patch fixes build errors and restores previous behavior by:
> >   - ensure PTP_1588_CLOCK=y in TI specific configs and CPTS will be built
> >   - use IS_REACHABLE(CONFIG_TI_CPTS) in code instead of IS_ENABLED()
>
> I don't understand what IS_REACHABLE() is needed for once all the other
> changes are in place. I'd hope we can avoid that. Do you still see
> failures without
> that or is it just a precaution. I can do some randconfig testing on your patch
> to see what else might be needed to avoid IS_REACHABLE().

I've not changed this part of original patch, but seems you're right.

I can drop it and resend, but, unfortunately, i do not have time today for full build testing.
Sorry.

By the way in ptp_clock_kernel.h
#if IS_REACHABLE(CONFIG_PTP_1588_CLOCK)


--
Best regards,
grygorii