On Sun, 5 Apr 2015, Steve Bangert wrote: > On Sat, 2015-04-04 at 15:48 -0400, Alan Stern wrote: > > > > > Is that really all? Was there a "UAS is blacklisted for this device" > > line in the kernel log? It looks like the usb-storage driver didn't do > > anything at all with the device. > > Yes that's it. Using xhci at super speed, blacklisting uas is ignored > and the uas module apparently loaded anyway. Blacklisting isn't enough. I don't know why it didn't prevent the module from being loaded, but it doesn't matter. Not only do you have to tell the system _not_ to load the uas driver; you also have to tell the system that it _should_ use the usb-storage driver. Otherwise usb-storage will see that the device is capable of using UAS and will avoid binding to it. To do this, you need to set the usb-storage "quirks" module parameter to "174c:55aa:u". The 'u' quirk means to ignore the possibility of using UAS. > Here's a small snipet of dmesg w/uas blacklisted in > usr/lib/modprobe.d/dist-blacklist.conf using xhci at super speed. > > > > > 3.329222] usb 1-10: new full-speed USB device number 10 using xhci_hcd > [ 3.494369] usb 1-10: New USB device found, idVendor=0cf3, > idProduct=0036 > [ 3.494372] usb 1-10: New USB device strings: Mfr=0, Product=0, > SerialNumber=0 That's not your device. The Vendor and Product IDs don't match and the speed is wrong. > [ 3.500030] usbcore: registered new interface driver usb-storage > [ 3.501375] usbcore: registered new interface driver uas > [ 3.502435] ums-realtek 1-9:1.0: USB Mass Storage device detected > [ 3.512254] scsi host5: usb-storage 1-9:1.0 That's not your device either. Your device doesn't use ums-realtek. > But with ehci or xhci w/usb2 cable blacklisting succeeded and a message > was printed in the logs. Also note the Quirk match. > > > [ 192.802720] xhci_hcd 0000:00:14.0: Endpoint 0x2 ep reset callback > called > [ 192.844585] usb 1-2: UAS is blacklisted for this device, using > usb-storage instead > [ 192.844588] usb-storage 1-2:1.0: USB Mass Storage device detected > [ 192.844990] usb-storage 1-2:1.0: Quirks match for vid 174c pid 55aa: > 400000 > [ 192.845004] scsi host5: usb-storage 1-2:1.0 > [ 192.845065] usbcore: registered new interface driver usb-storage In this case the blacklisting succeeded because the driver specifically checks for a SuperSpeed connection. Since you were using a USB-2 cable, the connection was only high speed. > Another usbmon trace but with the uas module renamed. It's the same as before, and for the same reason. 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
