Re: Likely issue with ch341 kernel-module/driver

[Ajay Garg]

I started in the morning to build the driver from the source provided
by the vendor, but it was written in the times of kernel-version 2.4,
and I got hopelessly stuck.

Wanting to take a break, I reset my setup, and VERY strangely, what I
now observe is ::

a)
I am NOT able to send anything from the embedded-system to
putty-session (nothing appears at all on the putty session).

b)
Receive is working perfectly (anything I type in the putty-session is
received fine in the embedded-application).


Not sure what the hell is going on :(

Also, as per http://lxr.free-electrons.com/source/drivers/usb/serial/ch341.c?v=3.16,
the particular serial-USB-adapter device is added into the id_table,
so seems supported as per say.


Additionally, the message has changed to

###########################################################
usb 2-2: device not accepting address 8, error -71
###########################################################



Completely lost :(

On Wed, Aug 26, 2015 at 11:45 PM, Johan Hovold <johan@xxxxxxxxxx> wrote:
> On Wed, Aug 26, 2015 at 08:09:30PM +0200, Peter Stuge wrote:
>> Johan Hovold wrote:
>> > On Wed, Aug 26, 2015 at 09:39:36PM +0530, Ajay Garg wrote:
>> ..
>> > > garbage characters transmitted from embedded-device
>> ..
>> > > It seems that there is some issue with the driver.
>> >
>> > Why do think it's a driver issue?
>>
>> I can confirm similar issues with the in-tree driver and my hardware.
>
> What hardware is that?
>
>> > > Any chance this can be made to work?
>>
>> Ajay, please try building the vendor driver. That works well for me.
>
> Yes, please do.
>
>> > > Any upgrade that might solve the issue?
>>
>> There is no upgrade. Someone needs to spend a day or so on adding
>> functionality from the vendor driver to the in-tree driver, in a
>> backwards-compatible way.
>>
>> > Looks like a hardware issue, I'm afraid.
>>
>> When I got garbage from the in-tree driver it was indeed a driver issue.
>
> That's good to hear. Care to write up a patch? :)
>
> Thanks,
> Johan



-- 
Regards,
Ajay
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