Subject: Re: [PATCH 2/14] nes: device structures and defines

From: Jeff Garzik <[email-masked]>
Date: Wed, 08 Aug 2007 12:33:24 -0400

Michael Buesch wrote:
> On Wednesday 08 August 2007 18:18:31 Roland Dreier wrote:
>>  > But there are indeed a few cases that look wrong.
>>
>> yes...
>>
>>  > arch/x86_64/kernel/pci-calgary.c:       writel(cpu_to_be32(val), target);
>>
>> eg this almost certainly wants to be
>>
>> 	writel(swab32(val), target);
>>
>> or something equivalent like
>>
>> 	__raw_writel(cpu_to_be32(val), target);
>> 	/* plus some suffficent memory ordering */
>>
>>  - R.
>>
>>
> 
> certainly, yes.
> Most likely the __raw_writel variant is portable, but I am not
> sure. Anybody sure?

Yes, it's portable.  You must however be aware of the guarantees that 
writel() provides and __raw_writel() does not:  no barriers or flushes, 
no endian conversions, no ordering constraints, ...  Probably a few more 
details I'm forgetting too :)

	Jeff