diff options
Diffstat (limited to 'arch/arm/plat-omap/dma.c')
| -rw-r--r-- | arch/arm/plat-omap/dma.c | 18 |
1 files changed, 16 insertions, 2 deletions
diff --git a/arch/arm/plat-omap/dma.c b/arch/arm/plat-omap/dma.c index c22217c..3ec7ec5 100644 --- a/arch/arm/plat-omap/dma.c +++ b/arch/arm/plat-omap/dma.c @@ -1024,12 +1024,26 @@ EXPORT_SYMBOL(omap_set_dma_callback); */ dma_addr_t omap_get_dma_src_pos(int lch) { + u32 cdac; dma_addr_t offset = 0; if (cpu_is_omap15xx()) offset = p->dma_read(CPC, lch); - else - offset = p->dma_read(CSAC, lch); + else { + /* + * CDAC != 0 indicates that the DMA transfer on the channel has + * been started already. + * If 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. + * This is valid since in fact the DMA has not yet progressed. + */ + cdac = p->dma_read(CDAC, lch); + if (likely(cdac)) + offset = p->dma_read(CSAC, lch); + else + offset = p->dma_read(CSSA, lch); + } if (IS_DMA_ERRATA(DMA_ERRATA_3_3) && offset == 0) offset = p->dma_read(CSAC, lch); |