Comment 13 for bug 1527491

26 Jan 2017; same problem

from syslog

Jan 26 08:36:17 USSMLTRDLinux02 kernel: [259338.868105] usb 2-1.1: new full-speed USB device number 38 using ehci-pci
Jan 26 08:36:17 USSMLTRDLinux02 kernel: [259338.961091] usb 2-1.1: New USB device found, idVendor=1a86, idProduct=7523
Jan 26 08:36:17 USSMLTRDLinux02 kernel: [259338.961097] usb 2-1.1: New USB device strings: Mfr=0, Product=2, SerialNumber=0
Jan 26 08:36:17 USSMLTRDLinux02 kernel: [259338.961099] usb 2-1.1: Product: USB2.0-Ser!
Jan 26 08:36:17 USSMLTRDLinux02 kernel: [259338.961389] ch341 2-1.1:1.0: ch341-uart converter detected
Jan 26 08:36:17 USSMLTRDLinux02 kernel: [259338.963275] usb 2-1.1: ch341-uart converter now attached to ttyUSB1
Jan 26 08:36:17 USSMLTRDLinux02 mtp-probe: checking bus 2, device 38: "/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.1"
Jan 26 08:36:17 USSMLTRDLinux02 mtp-probe: bus: 2, device: 38 was not an MTP device

$ uname -a
Linux USSMLTRDLinux02 3.13.0-107-generic #154~precise1-Ubuntu SMP Tue Dec 20 10:37:27 UTC 2016 i686 i686 i386 GNU/Linux

I do observe the associated access is ehci-pci, whereas the original post access was xhci_hcd

Also I have some CH341 bases RS485 interfaces, they work just fine, same VID:PID. The device having problems is RS232. These have a driver CD for Windows, works fine there.

sys;log for the RS485 device

Jan 26 08:48:04 USSMLTRDLinux02 kernel: [260046.435291] usb 2-1.4: USB disconnect, device number 37
Jan 26 08:48:07 USSMLTRDLinux02 kernel: [260049.195120] usb 2-1.4: new full-speed USB device number 39 using ehci-pci
Jan 26 08:48:07 USSMLTRDLinux02 kernel: [260049.288782] usb 2-1.4: New USB device found, idVendor=1a86, idProduct=7523
Jan 26 08:48:07 USSMLTRDLinux02 kernel: [260049.288788] usb 2-1.4: New USB device strings: Mfr=0, Product=2, SerialNumber=0
Jan 26 08:48:07 USSMLTRDLinux02 kernel: [260049.288791] usb 2-1.4: Product: USB2.0-Serial
Jan 26 08:48:07 USSMLTRDLinux02 kernel: [260049.289149] ch341 2-1.4:1.0: ch341-uart converter detected
Jan 26 08:48:07 USSMLTRDLinux02 kernel: [260049.291092] usb 2-1.4: ch341-uart converter now attached to ttyUSB2
Jan 26 08:48:07 USSMLTRDLinux02 mtp-probe: checking bus 2, device 39: "/sys/devices/pci0000:00/0000:00:1d.0/usb2/2-1/2-1.4"
Jan 26 08:48:07 USSMLTRDLinux02 mtp-probe: bus: 2, device: 39 was not an MTP device

I note in RS232 description:
Jan 26 08:36:17 USSMLTRDLinux02 kernel: [259338.961099] usb 2-1.1: Product: USB2.0-Ser!

and in RS485 description:
Jan 26 08:48:07 USSMLTRDLinux02 kernel: [260049.288791] usb 2-1.4: Product: USB2.0-Serial

interesting how the description in syslog also corrupts