Re: Calculating kernel logical address ..

[David S. Miller]

   From: "Richard B. Johnson" <[e-mail]>
   Date: Mon, 9 Sep 2002 14:00:35 -0400 (EDT)

   Well I just read Documentation/DMA-mapping.txt as advised by David
   and it seems as though it will no longer be possible to do what
   many programmers have been wanting to do, to wit:
   
   (1) In user-code, allocate a buffer.
   (2) Lock that buffer into memory.
   (3) Call some driver that DMAs data to/from that buffer.
   
Video capture drivers and ALSA layer in 2.5.x kernel do
this perfectly fine.  Perhaps you should have a look
at how they handle DMA on PCI.