Re: 2.4.21-pre4: PDC ide driver problems with shared interrupts

[Ross Biro]

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.

    Ross