diff options
| author | Peter Ujfalusi <peter.ujfalusi@ti.com> | 2011-12-09 13:38:00 -0800 |
|---|---|---|
| committer | Tony Lindgren <tony@atomide.com> | 2011-12-09 13:38:00 -0800 |
| commit | 06e8077b556a372871c04dd68f47e8c25e9ca348 (patch) | |
| tree | b792a9ad2ef20d6e837c6b1749ef817c6286b44e /arch/arm | |
| parent | 7ba966804f58ccd81375827a71222efaa131aa70 (diff) | |
| download | linux-06e8077b556a372871c04dd68f47e8c25e9ca348.tar.bz2 | |
ARM: OMAP2+: DMA: Workaround for invalid destination position
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>
Reviewed-by: Jarkko Nikula <jarkko.nikula@bitmer.com>
Signed-off-by: Tony Lindgren <tony@atomide.com>
Diffstat (limited to 'arch/arm')
| -rw-r--r-- | 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 a9983b695a18..002fb4d96bbc 100644 --- a/arch/arm/plat-omap/dma.c +++ b/arch/arm/plat-omap/dma.c @@ -1074,8 +1074,16 @@ dma_addr_t omap_get_dma_dst_pos(int lch) * omap 3.2/3.3 erratum: sometimes 0 is returned if CSAC/CDAC is * read before the DMA controller finished disabling the channel. */ - if (!cpu_is_omap15xx() && offset == 0) + if (!cpu_is_omap15xx() && offset == 0) { 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); + } if (cpu_class_is_omap1()) offset |= (p->dma_read(CDSA, lch) & 0xFFFF0000); |