On Wednesday 28 of August 2013 09:06:27 Linus Walleij wrote: > On Sun, Aug 11, 2013 at 7:59 PM, Tomasz Figa <tomasz.figa@xxxxxxxxx> wrote: > > The legacy S3C-DMA API required every period of a cyclic buffer to be > > queued separately. After conversion of Samsung ASoC to Samsung DMA > > wrappers somebody made an assumption that the same is needed for DMA > > engine API, which is not true. > > > > In effect, Samsung ASoC DMA code was queuing the whole cyclic buffer > > > > multiple times with a shift of one period per iteration, leading to: > > a) severe memory waste - up to 13x times more DMA transfer > > descriptors > > > > are allocated than needed, > > > > b) possible memory corruption, because further cyclic buffers were > > out > > > > of the original buffers, due to the offset. > > > > This patch fixes this problem by making the legacy S3C-DMA API use the > > same semantics as DMA engine (the whole cyclic buffer is enqueued at > > once) and modifying users of Samsung DMA wrappers in cyclic mode to > > behave appropriately. > > > > Signed-off-by: Tomasz Figa <tomasz.figa@xxxxxxxxx> > > Acked-by: Linus Walleij <linus.walleij@xxxxxxxxxx> > > If patch 1 thru 9 are uncontroversial now, maybe Vinod can apply > these for v3.12 so we can get less noise and risk of collissions > in the next merge window? > > Just an idea. That would be nice, leaving only Samsung-specific patches for the next merge window. (That would be patches 1 to 8, though, as 9 is a patch for ASoC that could be picked up by Mark Brown independently.) Best regards, Tomasz -- To unsubscribe from this list: send the line "unsubscribe linux-samsung-soc" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
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