Messages in this thread | | | Date | Wed, 5 Feb 2003 18:38:08 +0100 | From | Stephan von Krawczynski <> | Subject | Re: 2.4.21-pre4: PDC ide driver problems with shared interrupts |
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On 05 Feb 2003 18:34:55 +0100 Benjamin Herrenschmidt <benh@kernel.crashing.org> wrote:
> On Wed, 2003-02-05 at 18:19, Ross Biro wrote: > > Benjamin Herrenschmidt wrote: > > > > >While I agree with you here, I don't think it's what's happening. > > > /* clear INTR & ERROR flags */ > > > hwif->OUTB(dma_stat|6, hwif->dma_status); > > > > > > > > > > > You have way to much faith in the hardware. Promise is especially known > > for not keeping to the spec. I wouldn't trust the interrupt bit to be > > valid unless a dma is actually active, i.e. that > > > > hwif->OUTB(hwif->INB(dma_base)|1, dma_base); > > > > has actually been written. > > > > I've actually had a manufacturer tell me that they don't worry about the > > spec, just making things work with Windows. > > Ok, so that gives us 2 possibilities. The above problem, which would be > fixed by locking all around ide_dma_read/write (or rather in the > _caller_, seems better so we don't have to drop the lock for ATAPI). > > And a possible wraparound of waiting_for_dma if 255 IRQs come in from > whatever device we share the IRQ line with. > > I beleive both need fixing... > > Ben.
Ok, yet another small brick in the wall: this mb has 64bit/66MHz PCI slots. PDC is only 32bit/33MHz PCI. So it may well be that others are in fact _able_ to produce a damn lot more data/interrupts than the PDC. I am pretty astonished by the number of interrupts created by the 3com tg3 cards anyways...
-- Regards, Stephan - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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