On Sat, 12 Sep 2015, Hans-Peter Jansen wrote: > On Freitag, 11. September 2015 10:23:45 Alan Stern wrote: > > On Fri, 11 Sep 2015, Hans-Peter Jansen wrote: > > > > > > I still have trouble with storage devices on xhci ports, that disappear as > > > soon as I change to an ehci port. > > > > > > My current kernel version is 4.1.6. > > > Device is a Transcend TS-RDF8K USB3.0 sdcard reader, tested directly on > > > rear panel I/O USB3.0 port of a z97 series MB (ASUS Z97-A) with the > > > original cable, and a SanDisk Ultra 64GB SDXC media. > > > > > > > Can you post a usbmon trace showing what happens when the card reader > > is plugged in? Instructions are in the kernel source file > > Documentation/usb/usbmon.txt. > > With pleasure, Alan. > > Here we go, plugged the reader for about 20 secs, result attached. The usbmon trace clearly shows the problem: The card reader's firmware doesn't handle transfers larger than 64 KB properly. (That's a bit of a guess on my part; what the trace really shows is that transfers of length 120 KB and 72 KB failed whereas lengths 28 KB and below worked.) Anyway, you can supply a quirks parameter for the usb-storage module to force all transfers to be short: modprobe usb-storage quirks=8564:4000:m (That's the vendor and product IDs of your card reader, together with a flag to limit the Max number of sectors per transfer.) Does that fix the problem? Alan Stern -- 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
