Re: on-going discussion at [1], I've added support to EDMA driver to be able to accept scatter gather lists of arbitrary length, but still make use of only a certain MAX number of slots. Thus free-ing up the rest of the slots to other slave users. With this there is no need for slave drivers to query the EDMA driver how much is the MAX. It can send SG lists of any number of entries to DMA. Tested with various number of MAX slots , even just "1". In the case where it is 1, only 1-slot is used to transmit an entire set of scatter list. If only 1 slot is used for a channel, there is a performance impact, but it works. A DMA resources vs Performance tradeoff. [1] http://marc.info/?l=linux-omap&m=137416733628831&w=2 Joel Fernandes (5): dma: edma: Setup parameters to DMA MAX_SG_NR at a time dma: edma: Write out and handle MAX_SG_NR at a given time ARM: edma: Add function to manually trigger an EDMA channel dma: edma: Find missed events and issue them DMA: EDMA: Leave linked to Null slot instead of DUMMY slot arch/arm/common/edma.c | 21 +++++++ drivers/dma/edma.c | 113 ++++++++++++++++++++++++++---------- include/linux/platform_data/edma.h | 2 + 3 files changed, 104 insertions(+), 32 deletions(-) -- 1.7.9.5 -- To unsubscribe from this list: send the line "unsubscribe linux-omap" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
