tree 8d8b39fe1c77a937174b9d604f8cc554d18d4366
parent 5611cc4572e889b62a7b4c72a413536bf6a9c416
author Peter Ujfalusi <peter.ujfalusi@ti.com> 1323466680 -0800
committer Tony Lindgren <tony@atomide.com> 1323466680 -0800

ARM: OMAP2+: DMA: Workaround for invalid source position

If the DMA source position has been asked before the
first actual data transfer has been done, the CSAC
register does not contain valid information.
We can identify this situation by checking the CDAC
register:
CDAC != 0 indicates that the DMA transfer on the channel has
been started already.
When CDAC == 0 we can not trust the CSAC value since it has
not been updated, and can contain random number.
Return the start address in case the DMA has not jet started.

Note: The CDAC register has been initialized to 0 at dma_start
time.

Signed-off-by: Peter Ujfalusi <peter.ujfalusi@ti.com>
Reviewed-by: Jarkko Nikula <jarkko.nikula@bitmer.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>