[PARPORT] ppa driver broken in 2.2.0pre1


David Campbell (campbell@torque.net)
Thu, 31 Dec 1998 10:39:14 +0800


The ppa driver was broken due to a patch applied to the asm code to prevent
egcc complaining about "trashing registers" which is apparently not supported
for gcc (but gcc doesn't complain about it either).

This affects 2.2.0pre1 compiled for x86 machines (AXP machines use a C function
and not the broken asm).

The asm code exists for increased performance on 386/486 machines when using
nybble or byte modes (10-25%). There is almost no significant improvement
between the asm and C code for 586 or higher machines. I am working on a patch
to rectify the problem now and hopefully send it off in a couple of hours time.

This patch will require the use of egcc to obtain the performance on 386/486
machines equivalent of the 2.1.132 driver, otherwise a slight performance
degradation will occur (on these machines, every CPU cycle counts).

David Campbell

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This archive was generated by hypermail 2.0b3 on Wed 30 Dec 1998 - 21:41:14 EST