On Tuesday 10 April 2012, Marek Szyprowski wrote: > Before patch no 6, there were custom methods for all scatter/gather > related operations. They iterated over the whole scatter list and called > cache related operations directly (which in turn checked if we use dma > bounce code or not and called respective version). Patch no 6 changed > them not to use such shortcut for direct calling cache related operations. > > Instead it provides similar loop over scatter list and calls methods > from the current device's dma_map_ops structure. This way, after patch no > 7 these functions call simple dma_map_page() method for all standard > devices and dma bounce aware version for devices registered for dma > bouncing (with use different dma_map_ops). Ok, thanks for the explanation. > I can provide a separate set of scatter/gather list related functions for > the linear dma mapping implementation and dma bouncing implementation > if you think that the current approach is too complicated or > over-engineered. It's probably not needed, though I have not looked at the big picture with all the patches applied. which I should do at some point. Arnd -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>