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SubjectRe: [PATCH v3 01/12] misc: add driver for sequencer serial port
On 10/22/2010 08:48 AM, Arnd Bergmann wrote:
> On Friday 22 October 2010 14:39:33 Cyril Chemparathy wrote:
>>>> +/* Register Access Helpers */
>>>> +static inline u32 ssp_read(struct ti_ssp *ssp, int reg)
>>>> +{
>>>> + return __raw_readl(ssp->regs + reg);
>>>> +}
>>>> +
>>>> +static inline void ssp_write(struct ti_ssp *ssp, int reg, u32 val)
>>>> +{
>>>> + __raw_writel(val, ssp->regs + reg);
>>>> +}
>>>
>>> Why are the __raw functions used here?
>>>
>>
>> These registers are to be accessed native endian at all times, and
>> therefore the le32 conversion done otherwise is inappropriate.
>
> Won't that break on out-of-order CPUs that need the extra synchronization
> done in readl/writel?
>

AFAICS, ioremap()ed space on ARMv6 should be strongly ordered.

>
> ...
>

Thanks
Cyril.


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