Linux & DMA transfer (applied to 8245)

Callebaut Benoit callebaut at mailandnews.com
Fri Apr 25 00:58:44 EST 2003


Hi ,
I am implementing DMA transfers initiated by the processor for the MPC8245.
Since the standard pci_alloc_consistent take only a pci_dev structure but no
addresses, I added a configuration function to set the target address (PCI)
and the other parameters.
I can see that the DMA transfer is started, and finished (an interrupt is
generated) but I don't see the data copied on the target device ( DSP with a 4
MB memory window on PCI bus.)
My question is : What type of addreess must I give to configure the DMA
controller.
Are there also caching issues that may prevent good read/write operation
s? I suppose that the flushing og the cache done in pci_alloc_consistent is
enough.
Thanks
------------------------------------------------------------------------------
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Benoit Callebaut
Software Development Engineer
Barco | Control Rooms
Noordlaan 5, 8520 Kuurne, Belgium

Tel 	+32(0)56 36 84 28
Fax 	+32(0)56 36 86 05

mailto:benoit.callebaut at barco.com
http://www.barcocontrolrooms.com


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