On Sun, 15 Jul 2012, Sami Farin wrote: > On Sun, Jul 15, 2012 at 13:24:04 +0300, Sami Farin wrote: > > On Sat, Jul 14, 2012 at 16:20:12 -0400, Alan Stern wrote: > > ... > > > The usbmon trace doesn't show any reason for the write failures; the > > > second bug interferes before the device can report a reason. Working > > > around that other bug isn't quite so easy as the first -- it requires a > > > kernel patch (below). With that patch in place, maybe the usbmon trace > > > will give a little more information. > > > > > > Alan Stern > > > > I tried the patch with and without the usb_storage 400 quirk, no luck. > > Also, now with usb2 read/write speeds are 17/5 MB/s (advertized 85/40 for the card), > > with usb3 read speed 28 MB/s. > > these without 0x400 quirk: > usb2: read/write 31.6/20.3 MB/s, usb3: fail Forget about measuring throughput rates. If the device doesn't work, the rate doesn't matter. > usbmon with usb3: > https://docs.google.com/file/d/0B_EMXtsx7o56RFN4aUQzSUtfQ1k/edit This trace shows that the device crashed during a read and did not start working again, even after a reset. In past years I have found that Genesys's devices tend to be rather buggy. This card reader continues the tradition. Basically, although the firmware works reasonably well at high speed, the SuperSpeed support is too buggy to be usable. My advice is to exchange the card reader for one of a different brand. Alan Stern P.S.: Sarah, the lspci information shows this xHCI controller to be an ASM1042 controller from ASMedia. Is this one of those known to have the short-packet bug? The usbmon trace shows a cancelled transfer, for which 0 bytes must have been received, but with actual_length equal to the transfer_buffer_length. This would seem to indicate another type of bug in the host controller. Apparently it reported normal completion for a transfer that was cancelled. -- 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
