Demand mode DMA on the 960RP

[471034N@knotes.kodak.com]

From: Irv D Negrin

Hello,

I am using the demand mode DMA on channel 0 of the Intel 960RP.  The DMA
transfer data length is unknown because it is moving compressed data from
the local bus to host memory through the PCI bus as it's being compressed.
The data length specified in the DMA chain descriptor list is guaranteed
greater than the actual data.  When the data is exhausted, the DREQ is
deasserted, stalling the DMA, and an XINT6 interupt is sent to the 960
processor.  The DMA byte count is at some interim value in the current
chain and the next discriptor address is not null.  Is there anyway to
terminate the DMA and set channel 0 to idle in the XINT6 ISR without
forcing the local bus to complete the current chain (with dummy data) or
generating a bus fault?

Thanks in advance.

Irv Negrin
Eastman Kodak Company
471034N@knotes.kodak.com