Date: Tue, 2 Nov 1999 17:16:54 +0200 (IST)
From: Eli Zaretskii <eliz AT is DOT elta DOT co DOT il>
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To: Rob Kramer <robk AT pop1 DOT cyberway DOT com DOT sg>
cc: djgpp AT delorie DOT com
Subject: Re: DMA despair.
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On Tue, 2 Nov 1999, Rob Kramer wrote:

> The IRQ is determined by the BIOS, and can be queried through a PCI 
> register. The MPEG chip is the first PCI device, which is usually IRQ 
> 10h. I think the lack of interrupts is a symptom of my DMA-problems..

It is worth to verify the last assumption.

IRQ 10h, you say?  What interrupt does this trigger, and how do you set 
up the Interrupt Controller to generate an interrupt for IRQ 10h?  I only 
know about IRQ 0-15 (decimal).

If you mean IRQ 10 decimal, then try reading the Interrupt Request
Register and Interrupt In-Service Register of the slave Interrupt
Controller, and see if IRQ 10 is triggered. 

> Sorry, I realise my question is spinning out of control, in order for 
> anyone to give me the ultimate clue he/she would need to have 
> in-depth knowledge of the hardware in use. If I could  just be 
> certain the I'm doing things right with the DMA physical address.. 
> sigh. 

Based on your description and sample code, I don't see anything wrong 
with the buffer and its address.  That's why I suspect the problem is 
elsewhere.