[For new readers, the context is a discussion on how to allow large transfers in usbfs without having to break them up into small pieces. Forcing libusb to follow the many-small-pieces approach doesn't work well when an IN transfer ends in the middle with a short packet.] On Tue, 23 Jun 2009, Tim Roberts wrote: > For reference, the Windows solution is to lock the user-mode pages and > map them into kernel space, so it uses up address space but not memory. Mapping the pages into kernel space is irrelevant, isn't it? What matters is the DMA address used by the host controller or IOMMU, not the virtual address. > Windows limits a single EHCI bulk transfer to about 3 MB. Interrupt > endpoints don't have an artificial limit; you can do whatever will fit > before it squeals. I imagine users would be a lot happier with a 3 MB limit than a 16 KB limit. But don't there have to be alignment restrictions for it to work? Alan Stern -- 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
