David Laight wrote: > > We shouldn't need to make userspace start to worry about alignment at > > all. libusb worked in the past, before the link TRB fix went in. We > > *cannot* break userspace USB drivers. The breakage needs to be fixed in > > the USB core or the xHCI driver. > > Userspace doesn't care since everything gets copied into aligned > kernel fragments - otherwise the other usb controllers wouldn't work. OK, but not so great if someone wants to squeeze the most performance possible out of USB also from userspace. I'm going off on a tangent now but would it make sense to allow userspace to do alignment if it wants to, and have a way to tell the kernel when urb buffers are pre-aligned? //Peter -- 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