Re: [PATCH] drivers/char/mem.c: Add /dev/ioports, supporting 16-bit and 32-bit ports

[H. Peter Anvin]

On 05/09/2014 02:12 PM, Arnd Bergmann wrote:
> 
>> However, if we're going to have these devices I'm wondering if having
>> /dev/portw and /dev/portl (or something like that) might not make sense,
>> rather than requiring a system call per transaction.
> 
> Actually the behavior of /dev/port for >1 byte writes seems questionable
> already: There are very few devices on which writing to consecutive
> port numbers makes sense. Normally you just want to write a series
> of bytes (or 16/32 bit words) into the same port number instead,
> as the outsb()/outsw()/outsl() functions do.
> 

Indeed.  I missed the detail that it increments the port index; it is
virtually guaranteed to be bogus.

	-hpa


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