Re: Can we kill f inb_p, outb_p and other random I/O on port 0x80, in 2.6?

[Jamie Lokier]

linux@xxxxxxxxxxx writes:
> > So can we gradually kill inb_p, outb_p in 2.6?  An the other
> > miscellaneous users of I/O port 0x80 for I/O delays?
> 
> Actually, It's not easy.  The issue got debated a lot a few years ago.
> A read is also acceptable, and allows a few more ports to be
> potentially used, but that corrupts %al and thus bloats the code.

It bloats the code a lot less than udelay() calls or any other
solution which keeps the delay!

In the worst case, the bloat from a read _should_ be two bytes: "push
%eax; inb $80,%al; pop %eax".  Whereas a call to udelay is 5 bytes,
for a call instruction.

-- Jamie
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