On Mon, Sep 19, 2011 at 02:37:58PM -0700, Sarah Sharp wrote: > Add a new debufs file parameter that controls the number of segments used > when allocating a bulk endpoint ring. Matrix Vision has a libusb program > for their USB 2.0 cameras that submits a number of very large transfers. > The xHCI driver ends up rejecting some transfers because it doesn't have > enough room on the one bulk ring segment. By experimentation, their > program works if 20 bulk segments are allocated. Point Grey also has a > USB 3.0 webcam that needs more than one bulk segment. > > We really need to fix this by adding dynamic ring segment allocation, but > that code is a bit complex and will take a while to write. To ensure > Matrix Vision's libusb program works when their device is connected under > an xHCI host, add a debufs file to allow users to increase the number > of bulk endpoint ring segments. This is a temporary fix, and should be > removed once the xHCI driver has dynamic segment allocation. Once you add a userspace api like this, you can't ever remove it, so I would recommend not doing this. So either just keep the file around and don't have it do anything, or just put this in sysfs for real and keep it there. greg k-h -- 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
