From mboxrd@z Thu Jan  1 00:00:00 1970
From: robert.jarzmik@free.fr (Robert Jarzmik)
Date: Mon, 06 Oct 2014 23:44:52 +0200
Subject: [PATCH] Revert "ARM: pxa: call debug_ll_io_init for earlyprintk"
In-Reply-To: <6310030.SmNYckCtJ4@wuerfel> (Arnd Bergmann's message of "Mon, 06
 Oct 2014 23:18:43 +0200")
References: <1412602320-22896-1-git-send-email-dbaryshkov@gmail.com>
 <87a959aten.fsf@free.fr> <20141006210209.GA21019@og3k>
 <6310030.SmNYckCtJ4@wuerfel>
Message-ID: <871tqkc1pn.fsf@free.fr>
To: linux-arm-kernel@lists.infradead.org
List-Id: linux-arm-kernel.lists.infradead.org

Arnd Bergmann <arnd@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 ...

-- 
Robert