Takashi Iwai wrote:

All?  No, only a few...
For PCI, usually pci_set_dma_mask() and pci_set_consistent_dma_mask()
are used, of course.

Hmm, ok I was wrong.  I took this code from the ASoC at91 driver.

Unfortunately, I don't understand what this code is trying to do.  The AT91 
driver isn't documented, so I don't even know if I need it.  Can someone explain 
what all this is?  What's the alternative to using a static global?

-- 
Timur Tabi
Linux kernel developer at Freescale