On 295, 10 22, 2007 at 12:18:08PM -0400, Lennart Sorensen wrote: > On Mon, Oct 22, 2007 at 07:33:23PM +0400, Andrey Panin wrote: > > So the card probably generates screaming interrupt... that's bad. > > I found some docs for IT887x chips, according to these docs IT887x > > have simple interrupt controller inside. Further investigation is needed. > > > > Can you post output of lspci -xxx ? > > Is it possible they put a chip on to generate a PCI interrupt on perhaps > PCIB on the slot from the serial chips directly, so that they didn't > have to turn interrupts from the serial chips into a signal that forces > the parallel port to generate an interrupt? After all that would reduce > latency, and if you use PCIA for the parallel port, PCIB for the first > serial chip and PCIC for the second, you might get a much more efficient > design, although the driver would have to register all those IRQs.
I dont think so. IT887x has builtin interrupt controller which multiplexes 16 external IRQ pins with IRQs from builtin devices (parallel port, UARTs and GPIO) into single INTA# line. IT887x also contains 8-bit ISA-like bus and 16 chip select lines and it's all you need to glue UARTs to PCI bus. I suspect that it's interrupt controller problem, probably edge/level triggered settings. > What IRQ is each PCI device in that system using right now? perhaps we > could figure out what irq 17 would be on that PCI slot. -- Andrey Panin | Linux and UNIX system administrator [EMAIL PROTECTED] | PGP key: wwwkeys.pgp.net
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