If the DMA destination position has been asked before the first actual data transfer has been done, the CDAC register still contains 0 (it is initialized to 0 at omsp_dma_start). If CDAC == 0, return the programmed start address.
Signed-off-by: Peter Ujfalusi peter.ujfalusi@ti.com --- arch/arm/plat-omap/dma.c | 10 +++++++++- 1 files changed, 9 insertions(+), 1 deletions(-)
diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c index 38b0d44..9186491 100644 --- a/arch/arm/plat-omap/dma.c +++ b/arch/arm/plat-omap/dma.c @@ -1066,8 +1066,16 @@ dma_addr_t omap_get_dma_dst_pos(int lch)
if (cpu_is_omap15xx()) offset = p->dma_read(CPC, lch); - else + else { offset = p->dma_read(CDAC, lch); + /* + * CDAC == 0 indicates that the DMA transfer on the channel has + * not been started (no data has been transferred so far). + * Return the programmed destination start address in this case. + */ + if (unlikely(!offset)) + offset = p->dma_read(CDSA, lch); + }
/* * omap 3.2/3.3 erratum: sometimes 0 is returned if CSAC/CDAC is