Subject: [PATCH 2/3] ARM: EXYNOS: remove unused register offset definition

From: [email-masked] (Krzysztof Kozlowski)
Date: Wed, 24 Feb 2016 08:47:16 +0900

On 23.02.2016 18:11, pankaj.dubey wrote:
> Hi Krzysztof,
> 
> On Tuesday 23 February 2016 05:33 AM, Krzysztof Kozlowski wrote:
>> On 22.02.2016 19:03, Pankaj Dubey wrote:
>>> This patch cleans up map.h by removing unused register offset
>>> and changing EXYNOS4 to EXYNOS in header comment section.
>>>
>>> Signed-off-by: Pankaj Dubey <[email-masked]>
>>> ---
>>>  arch/arm/mach-exynos/include/mach/map.h | 9 +--------
>>>  1 file changed, 1 insertion(+), 8 deletions(-)
>>>
>>> diff --git a/arch/arm/mach-exynos/include/mach/map.h b/arch/arm/mach-exynos/include/mach/map.h
>>> index 351e839..c48ba4f 100644
>>> --- a/arch/arm/mach-exynos/include/mach/map.h
>>> +++ b/arch/arm/mach-exynos/include/mach/map.h
>>> @@ -2,7 +2,7 @@
>>>   * Copyright (c) 2010-2011 Samsung Electronics Co., Ltd.
>>>   *		http://www.samsung.com/
>>>   *
>>> - * EXYNOS4 - Memory map definitions
>>> + * EXYNOS - Memory map definitions
>>>   *
>>>   * This program is free software; you can redistribute it and/or modify
>>>   * it under the terms of the GNU General Public License version 2 as
>>> @@ -14,12 +14,6 @@
>>>  
>>>  #include <plat/map-base.h>
>>>  
>>> -/*
>>> - * EXYNOS4 UART offset is 0x10000 but the older S5P SoCs are 0x400.
>>> - * So need to define it, and here is to avoid redefinition warning.
>>> - */
>>> -#define S3C_UART_OFFSET			(0x10000)
>>> -
>>>  #include <plat/map-s5p.h>
>>
>> This does not look good. The S3C_UART_OFFSET is used in plat/map-s5p.h.
>>
> 
> Actually it's just defined there but not getting used anywhere. In fact
> we can remove it from there also.

The point is that your patch introduce changes. Before S3C_UART_OFFSET
was defined to 0x10000, after (because of #ifndef) it will be 0x400.
Description of "unused" is not accurate. Unused stuff does not impact
anything.

> So I submitted another patch to
> cleanup such redundant register definitions from plat/map-s5p.h.

That would be good.

> Only platform using S3C_UART_OFFSET is s3c64xx and its using definition
> from map-s3c.h. I have compiled all related platform defconfigs and
> found no issues because of removal of S3C_UART_OFFSET from map-s5p.c and
> map.h.

The compilation is not a test. You compiled something like this:
-#define S3C_UART_OFFSET			(0x10000)
 #ifndef S3C_UART_OFFSET
 #define S3C_UART_OFFSET         (0x400)
 #endif

... and found no errors. Of course there are no compilation errors! But
the value has changed!

Best regards,
Krzysztof