On Sun, Sep 29, 2013 at 9:58 PM, Alan Stern <stern@xxxxxxxxxxxxxxxxxxx> wrote: > On Sun, 29 Sep 2013, Markus Rechberger wrote: > >> >> > Do you have a userspace test program that we can use to verify that this >> >> > does work, and that others can use to run on some different platforms to >> >> > verify that this is actually faster? >> >> > >> >> >> >> You will need one of our devices for testing I guess. Some scanners >> >> (which use USBFS) or other low speed devices won't really utilize >> >> usbfs too much. I think I could provide some grabber device for >> >> testing if you want to. >> > >> > So no test userspace program you can knock up for us? I really hate >> > adding new core functionality to the kernel that I have no way of >> > testing at all, that's a recipe for it quickly breaking... >> > >> >> Well do you have any device which has a userspace driver? Without a >> device you can barely test it. >> There's a settopbox company which added the backported patch to Linux >> 3.2 they use USB cardreaders and even tested the devices with and >> without mmap support. >> I doubt that the SG support has any good testing on low end systems, >> I'm worried that it will introduce those latency issues again which we >> saw with 15k buffers. > > There are lots of userspace drivers based on libusb or libusbx. If you > post an enhancement for libusbx to make use of your buffer mappings, those are free to adapt their libraries to use that feature (see first post how to use the ioctls). You need to find a reasonable application for those patches, I do not know anyone else using such a heavy bulk or isochronous application on low end systems not even on high end systems (otherwise you'd very likely be able to find more such kernel allocation messages on the internet and not only from us, obviously they all link to our forum or devices). VMWare, Qemu or Xen might be a good target for testing (when passing through windows requests and using a camera in windows). I'll try to post some videos from the intel atom using our driver with the legacy mode (basically the normal way without mmap) and enhanced one with mmap isochronous and bulk. Markus -- 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
