5 Replies Latest reply on Sep 12, 2018 9:31 AM by elem2018

    USB Mass Storage can't be detected as /dev/sdb

    elem2018

      Hello,

       

      I followed the following instructions: (switch 2 is on the low position)

      -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

      For flashing kernel and rootfs, the eMMC space needs to be mounted, we will use uboot ums command for that.

       

      1. => ums 0 mmc 0 

      2lbopp4.jpg Checking the emmc device...In most cases the emmc device will be sdb unless you have multiple mass storage device connected to your PC.

      + expand sourceview plain

       

      1. $ ls /dev/sd* 

      mjwgle.jpg

      -------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------

       

      After typing  ums 0 mmc 0, I can see one USB device (Netchip usb download gadget) is detected in VM Ubuntu 14.04.  Dmesg gives the following messages:

      ...

      [  997.389492] usb 1-1: new high-speed USB device number 2 using ehci-pci

      [  997.649479] usb 1-1: New USB device found, idVendor=0525, idProduct=a4a5

      [  997.649489] usb 1-1: New USB device strings: Mfr=1, Product=2, SerialNumber=3

      [  997.649492] usb 1-1: Product: USB download gadget

      [  997.649493] usb 1-1: Manufacturer: FSL

      [  997.712231] usb-storage 1-1:1.0: USB Mass Storage device detected

      [  997.717282] usb-storage 1-1:1.0: Quirks match for vid 0525 pid a4a5: 10000

      [  997.717444] scsi host33: usb-storage 1-1:1.0

      [  997.725268] usbcore: registered new interface driver usb-storage

      [  997.740037] usbcore: registered new interface driver uas

      [ 1020.196637] usb 1-1: reset high-speed USB device number 2 using ehci-pci

      [ 4042.905267] hrtimer: interrupt took 11121686 ns

      ....

       

      it is clear that the usb download gadget is found, but  fdisk -l doesn't show the /dev/sdb

       

      $ sudo fdisk -l

      Disk /dev/sda: 536.9 GB, 536870912000 bytes

      255 heads, 63 sectors/track, 65270 cylinders, total 1048576000 sectors

      Units = sectors of 1 * 512 = 512 bytes

      Sector size (logical/physical): 512 bytes / 512 bytes

      I/O size (minimum/optimal): 512 bytes / 512 bytes

      Disk identifier: 0x000928fe

       

      Device Boot      Start         End      Blocks   Id  System

      /dev/sda1   *        2048  1031798783   515898368   83  Linux

      /dev/sda2      1031800830  1048573951     8386561    5  Extended

      /dev/sda5      1031800832  1048573951     8386560   82  Linux swap / Solaris

       

      Would you please tell me how can I get the usb download gadget detected as /dev/sdb ?

      In Google unfortunately I can't find any solution. Any hint will be appreciated.

      Thanks

       

      Elem

        • Re: USB Mass Storage can't be detected as /dev/sdb
          14rhb

          What does lsblk command give you?

           

          Rod

          • Re: USB Mass Storage can't be detected as /dev/sdb
            lui_gough

            I'm not familiar with the hardware you're dealing with .... but some suggestions would be

             

            Perhaps try a different USB drive or device - your particular unit seems to have known problems under Linux, specifically this line:

            [  997.717282] usb-storage 1-1:1.0: Quirks match for vid 0525 pid a4a5: 10000

            That seems to imply that this particular device has some issues with its behaviour that causes strange behaviour and some workarounds are being applied. It's worth trying a different drive just to see if it is the drive itself or something else.

             

            Another thing which seems a little strange to me is that the drive seems to be registered using the uas driver and then it seems to be reset/dropped out after a while:

            [  997.740037] usbcore: registered new interface driver uas

            [ 1020.196637] usb 1-1: reset high-speed USB device number 2 using ehci-pci

            This seems to imply to me that your device is behaving like a USB external hard drive/SSD using a bridge chip (maybe)? It's seemingly confusing the operating system as normally UASP is only used over USB 3.0 interfaces, and it's connected using EHCI (USB 2.0) rather than xHCI (USB 3.0). I'd try using a USB 2.0 only bridge board or enclosure, or a non UASP capable bridge chip as an alternative, or even a USB 3.0 one but with a different chipset. Otherwise check the power supply to the drive (if it needs a high amount of power, it might not work) and the cable (esp if using cheap USB-OTG cable, this could be a source of issues). Maybe disabling the UAS driver could help.

             

            - Gough

              • Re: USB Mass Storage can't be detected as /dev/sdb
                elem2018

                According  to your hints I tried the same process wiht a pure 4-Port USB 2.0 hub instead of previous 4-Port USB 2.0/3.0 hub. But the results are the same.  WARP7 is deteced firstly as USB storage device but resetted subsequently.

                Finally I noticed that the USB 2.0 driver on my laptop is virtual ehci-pci driver because I use VM Ubuntu as guest system. So I changed to standalone ubuntu box and tried the same process again, and now it works just fine, without any issue.

                So the solution is to use linux box instead of the VM linux guest.  This case can be closed.

                -Xi