[PATCH v3/resend] ARM: shmobile: Add early debugging support using SCIF(A)

[Geert Uytterhoeven]

On Thu, Nov 6, 2014 at 2:26 PM, Arnd Bergmann <arnd at arndb.de> wrote:
>> >> +     {
>> >> +             .virtual        = 0xffe40000,
>> >> +             .pfn            = __phys_to_pfn(0xffe40000),
>> >> +             .length         = SZ_64K,
>> >> +             .type           = MT_DEVICE_NONSHARED
>> >> +     },
>> >> +#endif /* CONFIG_DEBUG_R8A7779_SCIF2 */
>> >>  };
>> >
>> > This should be done automatically if you call debug_ll_io_init() or
>> > have an empty map_io() callback.
>>
>> On r8a7779 map_io() is not empty, but it didn't cover the SCIF registers,
>> cfr. the commit log:
>>
>> > >   4. On SoCs using the legacy machine_desc.map_io(), an identity mapping
>> > >      of the SCIF(A) registers must be set up in .map_io(). On all but
>> > >      r8a7779 this was already done.
>
> Ok. You can of course just call debug_ll_io_init() manually from the
> map_io function, it will create the same mapping.

Good idea, that would indeed simpify the logic, both in Kconfig and
renesas-scif.S.

I gave it a try. On Armadillo it worked, on kzm9g it didn't.
Probably the virtual address choice is wrong.

As I can't test it on the other boards using map_io(), I'd like to
keep this as-is
for now. We can migrate them gradually later.

Gr{oetje,eeting}s,

                        Geert

--
Geert Uytterhoeven -- There's lots of Linux beyond ia32 -- geert at linux-m68k.org

In personal conversations with technical people, I call myself a hacker. But
when I'm talking to journalists I just say "programmer" or something like that.
                                -- Linus Torvalds