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Commit 06e8077b authored by Peter Ujfalusi's avatar Peter Ujfalusi Committed by Tony Lindgren
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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: default avatarPeter Ujfalusi <peter.ujfalusi@ti.com>
Reviewed-by: default avatarJarkko Nikula <jarkko.nikula@bitmer.com>
Signed-off-by: default avatarTony Lindgren <tony@atomide.com>
parent 7ba96680

arch/arm/plat-omap/dma.c

+9 −1
Original line number Diff line number Diff line
@@ -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);