Re: Trouble with sound/mips/au1x00.c AC97 driver

[Andrew Dyer <adyer@righthandtech.com>]

Ralf Baechle wrote:
> For the general MIPS case (Alchemy may provide guarantees I don't know of)
> a SYNC instruction is not sufficient to ensure that a write has actually
> been reached by the device.  It may just like on PCI take a read from the
> same device again:
I just looked it up.

Section 2.4.5 of the Alchemy Au1550 datasheet says that a SYNC is 
guaranteed to commit the write buffer to memory.
Whoever is looking at this should also pay attention to the CCA bits in 
the TLB mapping the registers (Section 2.3.6 of the manual) or the fixed 
regions (depending on the VA used) to make sure that merging and 
gathering are turned off.
--
Andrew Dyer <adyer@righthandtech.com>
Sr. Engineer
RightHand Technologies, Inc.
6545 N. Olmsted Ave.
Chicago, IL 60631
(773) 774-7600 x111