On Thu, 2013-08-29 at 18:05 -0500, Joel Fernandes wrote: > The following series adds support to EDMA driver to enable DMA of > scatter-gather lists of arbitrary length, but still make use of only > a certain MAX number of slots at a time for a given channel. Thus > free-ing up the rest of the slots to other slaves/channels. With this > there is no need for slave drivers to query the EDMA driver about how > much is the MAX it can send at a time as done in [1]. Drivers can send > SG lists of any number of entries to DMA. Reference discussion at [2]. > > With this, all the patches for MMC and EDMA related to "sg limits" can be > dropped. > > Tested omap-aes and omap_hsmmc drivers with different MAX number of slots, > even just 1. In the case where it is 1, only 1-slot is used to DMA an > entire scatter list of arbitrary length. > Since this series touches EDMA private API code also shared with davinci-pcm, > playback of a 16-bit 44.1KHz audio file with davinci-pcm has been tested. > > Sample test run with 1 vs 16 (MAX number of slots/SG) in omap-aes driver: > MAX slots = 1: > (128 bit key, 8192 byte blocks): 1266 operations in 1 seconds (10371072 bytes) > MAX slots = 16: > (128 bit key, 8192 byte blocks): 1601 operations in 1 seconds (13115392 bytes) > > Note: For the above test, 8K buffer is mapped into SG list of size 2 so > only 2 slots are required. So beyond size 2, there will not be any noticeable > performance improvement. But above experiment just shows as proof of concept > that even using 1 slot is managed by just DMA'ing 1 SG entry at a time. much better series, thanks I think i am okay with this, if anyone has objections pls speak up. Also I need ack on the ARM patch 3/6 before I can carry this. -- Vinod Koul Intel Corp. -- 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
