On Fri, Oct 14, 2011 at 08:33:29AM -0600, Greg KH wrote: > On Fri, Oct 14, 2011 at 10:05:41AM -0400, Alan Stern wrote: > > No, a much better approach is to remove all limits on individual > > transfer sizes and instead have a global limit on the total amount of > > all usbfs buffers in use at any time. Maybe something like 16 MB; at > > SuperSpeed, that's about about 30 ms worth of data. > > That sounds quite reasonable. Alan, won't this global limit on the usbfs URB buffer size effect userspace drivers that are currently allocating large amounts of buffers, but still respecting individual buffer limit of 16KB? It seems like the patch has the potential to break userspace drivers. I think that Point Grey's USB 3.0 webcam will be attempting to queue a series of bulk URBs that will be bigger than your 16MB global limit. Tim, what is the total size of buffers that will be in flight at any one time for your device? Sarah Sharp -- 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
