Re: [PATCH] avr32: fix build error in atstk1006_defconfig

[Andreas Bießmann]

On 16.10.2012 11:17, Hans-Christian Egtvedt wrote:
> Around Tue 16 Oct 2012 15:19:27 +0800 or thereabout, Josh Wu wrote:
>> fixed the following compile error when use avr32 atstk1006_defconfig:
>>   drivers/mtd/nand/atmel_nand.c: In function 'pmecc_err_location':
>>   drivers/mtd/nand/atmel_nand.c:639: error: implicit declaration of function 'writel_relaxed'
>>
>> which was introduced by commit 1c7b874d33b463 ("mtd: at91: atmel_nand: add Programmable Multibit ECC controller support").
>> The PMECC for nand flash code uses writel_relaxed(). But in avr32, there is no macro "writel_relaxed" defined. This patch add writex_relaxed macro definitions.
>>
>> Signed-off-by: Josh Wu <josh.wu@xxxxxxxxx>
>> ---
>>  arch/avr32/include/asm/io.h |    4 ++++
>>  1 file changed, 4 insertions(+)
>>
>> diff --git a/arch/avr32/include/asm/io.h b/arch/avr32/include/asm/io.h
>> index cf60d0a..fc6483f 100644
>> --- a/arch/avr32/include/asm/io.h
>> +++ b/arch/avr32/include/asm/io.h
>> @@ -165,6 +165,10 @@ BUILDIO_IOPORT(l, u32)
>>  #define readw_be			__raw_readw
>>  #define readl_be			__raw_readl
>>  
>> +#define writeb_relaxed			writeb
>> +#define writew_relaxed			writew
>> +#define writel_relaxed			writel
>> +
> 
> I'm wondering if they should be something similar to SH arch:
> 
> #define writeb_relaxed(v,c) ((void)__raw_writeb((__force u8)ioswabb(v),c))

I think it is OK to just use the writeX here. These are in fact an
inlined function built out of a macro. The inlined function does nearly
what you have written down here and in contrast to the ARM version omits
the memory barrier.
The main difference between __raw_ access and the writeX/readX access
for AVR32 is this little __swizzle_addr_. It takes the configuration of
SMC (8/16/32 bit access) into account which would be omitted when we
switch to __raw_ accessors here. This would be a major change if one
used the writeX/readX accessors before and switched the SMC to something
different than 32 Bit access.

Best regards

Andreas Bießmann
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