Re: ch341.c does not work with new ch34x devices

Re: ch341.c does not work with new ch34x devices

[Greg KH]

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-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: ch341.c does not work with new ch34x devices

[Liangent]

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-hQyY1W1yCW8ekmWlsbkhG0B+6BGkLq7r@public.gmane.org> 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-u79uwXL29TY76Z2rM5mHXA@public.gmane.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html

Re: Re: ch341.c does not work with new ch34x devices

[Karl Palsson]

[-- Attachment #1: Type: text/plain, Size: 208 bytes --]


I'm seeing this as well, I've got some work in progress towards this,
but not finding the time I'd hoped.  CH340 devices work "fine" with the
current linux driver, but CH341, very very very flaky, if at all.