Am Thursday 29 January 2009 17:30:27 schrieb David Vrabel: > Alan Stern wrote: > > > > Pushing scatterlists down to the HCD level would involve several > > nontrivial changes to the code. The issue of the buffer lengths is > > just one of them, although it is perhaps the most vexing. > > I don't see where the complexity is. The HCD simply fills the > hardware's s-g list structures based on the s-g list in the URB. > > Obviously, none of the existing HCDs can support s-g lists in this > manner and should continue to only accept URBs without s-g lists. Meaning that drivers that want to take advantage of this would need to test for this ability and have different code paths for it. Therefore I would prefer chained URBs despite their size. For HCDs whose maximum chain length is exceeded usbcore could walk the chain and submit them iteratively. Regards Oliver -- To unsubscribe from this list: send the line "unsubscribe linux-usb" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
