[PATCH] Revert "ARM: pxa: call debug_ll_io_init for earlyprintk"
Arnd Bergmann
arnd at arndb.de
Tue Oct 7 02:18:32 PDT 2014
On Monday 06 October 2014 23:44:52 Robert Jarzmik wrote:
> Arnd Bergmann <arnd at arndb.de> writes:
>
> > On Monday 06 October 2014 16:02:09 Andrew Ruder wrote:
> >> On Mon, Oct 06, 2014 at 09:29:36PM +0200, Robert Jarzmik wrote:
> >> > Actually, I have a question for Andrew : was your commit aimed at the 3 or 4
> >> > available UARTs (ie. in peripheral address space), or is it a case where an
> >> > external UART is mapped on the system bus (if that is possible) ?
> >>
> >> My apologies! I'm actually on a really long-term project of getting my
> >> board (similar to zeus board already in the kernel) fully running off of
> >> devicetree. For this particular board, all of the UARTS are on the
> >> system bus and not the built in ones. But yes - I do see how the
> >> built-in UARTS would overlap and hit the BUG_ON on other boards. Any
> >> thoughts on a better way of solving this than just reverting the patch
> >> back into only working on the built-in UARTs?
> >
> > I think the best way forward is to make the built-in UARTs work with
> > debug_ll_io_init and then apply your patch again.
> Yes, and that means revert, right ?
>
> The best approach I'd see for pxa_map_io() would be to call debug_ll_io_init()
> conditionally, when the CONFIG_DEBUG_UART_PHYS is defined and is not within the
> peripheral bus range, ie. within [ PERIPH_PHYS .. PERIPH_PHYS + PERIPH_SIZE ].
>
> I don't see how to do it without ugly ifdefery though such as :
> #if defined(CONFIG_DEBUG_UART_PHYS) && \
> ((CONFIG_DEBUG_UART_PHYS < PERIPH_PHYS) || (CONFIG_DEBUG_UART_PHYS >=
> PERIPH_PHYS + PERIPH_SIZE))
> debug_ll_io_init();
> #endif
>
> But that's awfull, there should be another better way ...
Can't you just define CONFIG_DEBUG_UART_VIRT outside of the existing
mappings? It doesn't have to use the same mapping as PERIPH_PHYS.
Arnd
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