[alsa-devel] [PATCH 0/2] OMAP2+: DMA: fix src/dst position reporting
jarkko.nikula at bitmer.com
Tue Nov 1 20:26:06 CET 2011
On 10/31/2011 04:20 PM, Peter Ujfalusi wrote:
> If the user asks for the sDMA current position before the first
> data has been transmitted (before the first DMA request has been
> generated), the reported position is not valid:
> src position: CSAC is uninitialized
> dst position: CDAC is 0
> The return values in both case considered invalid.
> This sitation can be identified by checking if the CDAC register
> is 0 (it is initialized to 0 in omap_dam_start call).
> In this case return the programmed source/destination address.
> The affected omap_get_dma_src_pos/omap_get_dma_dst_pos functions
> are used by the audio stack mainly for checking the current position
> of the audio stream.
> Peter Ujfalusi (2):
> OMAP2+: DMA: Workaround for invalid source position
> OMAP2+: DMA: Workaround for invalid destination position
> arch/arm/plat-omap/dma.c | 25 ++++++++++++++++++++++---
> 1 files changed, 22 insertions(+), 3 deletions(-)
Reviewed-by: Jarkko Nikula <jarkko.nikula at bitmer.com>
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