"Jochen Hoenicke" writes:
>It is not easy to autodetect the irq number for parallel ports. AFAIK
>only ECP makes it possible to detect the interrupt. You should always
>use the "irq=" option of parport_pc.
I have noticed that with some parallel port hardware (when in normal
bi-dir PS/2 mode), a single spurious interrupt is generated when I
turn on the IRQ-enable bit in the control register. I have never
found any documentation of this "feature" but I think it may be
there to aid in IRQ autodetection. In particular I know my Dell
Optiplex GX1 at work does this.
I don't think the kernel tries using this trick to detect IRQ
interrupts currently... I keep meaning to write a patch.
-Jer
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This archive was generated by hypermail 2b29 : Fri Jul 07 2000 - 11:56:41 EDT