Re: [PARPORT] Buffer read/write verification

Dale Whitfield (
Fri, 19 Mar 1999 17:37:39 +0000

>If you're dealing with 256k of data the overhead of set_fs() is negligible. I
>agree it's not ideal that you have to do this but the alternative would be to
>force any driver that *does* want to supply data from user space (eg, lp) to
>bounce it through a kernel buffer.

Agree the overhead on a large buffer is negligible. 256k is not a frequent
occurrence but sending numerous small amounts of data to the camera are.

>It might possibly be worth investigating the idea of providing "fast path"
>IEEE1284 functions for at least the common cases.

I thought of special-casing calls which only involve one byte of data. Problem
is you can justify a fastpath function for most of the 8 variations of ecp-mode
read/write calls alone.


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This archive was generated by hypermail 2.0b3 on Sun 28 Mar 1999 - 17:02:40 EST