I'm connecting it to an external modem on the RS232 side. If I use some other program to connect to the modem, it reports "modem not responding". To debug further I'm minicom'ing to it. Once connected, I type "AT" then press Enter. Screen output is pasted below (with Local Echo set to No and Hex Display set to Yes): "Good" driver: Welcome to minicom 2.7 OPTIONS: I18n Compiled on Jan 1 2014, 09:30:18. Port /dev/ttyUSB0, 22:53:12 Press CTRL-A Z for help on special keys 41 54 0d 0d 0a 4f 4b 0d 0a "Bad" driver: Welcome to minicom 2.7 OPTIONS: I18n Compiled on Jan 1 2014, 09:30:18. Port /dev/ttyUSB0, 23:09:35 Press CTRL-A Z for help on special keys 01 14 0d -Liangent On 12/13/14, Greg KH <gregkh@xxxxxxxxxxxxxxxxxxx> wrote: > On Sat, Dec 13, 2014 at 01:15:07PM +0800, Liangent wrote: >> Hello, >> >> I bought a new USB-RS232 cable and the system loads ch341.ko for me >> (Debian with kernel 3.14-2-amd64 and 3.16.0-4-amd64). However this >> module does not work with my cable (/dev/ttyUSB0 appears but the >> serial device doesn't work properly) while the driver provided by chip >> vendor[1] works (this driver doesn't compile on kernel 3.16 anymore >> but 3.14 is fine). >> >> This is dmesg output with the vendor-provided driver. >> >> [ 1900.070021] usb 2-1.4: new full-speed USB device number 5 using >> ehci-pci >> [ 1900.163218] usb 2-1.4: New USB device found, idVendor=1a86, >> idProduct=7523 >> [ 1900.163227] usb 2-1.4: New USB device strings: Mfr=0, Product=2, >> SerialNumber=0 >> [ 1900.163232] usb 2-1.4: Product: USB2.0-Ser! >> [ 1900.163887] ch34x 2-1.4:1.0: ch34x converter detected >> [ 1900.165052] usb 2-1.4: ch34x converter now attached to ttyUSB0 >> >> For the record I've used an old cable which works fine with the >> built-in ch341.ko driver, but unfortunately that cable is not in my >> hand anymore. >> >> [1] http://wch.cn/downloads.php?name=pro&proid=177 > > That device should "just work" with the in-kernel driver. The fact that > it is autoloaded is a good sign something is right. > > So no data flows through the device at all when using it, or are there > other symptoms of "not working"? > > thanks, > > greg k-h > -- 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