Re: ch341: support new device types (Was: Re: PROBLEM: ch341 module fails with EPROTO when I plug-in Arduino board)

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

 



Sorry for misunderstanding, I've tested the behavior of Arduino board
on 2 machines and the result is following:

PASSED - Arduino board connected successfully
FAILED - ch341 errors arose

1st machine [USB 3.0] -- Linux 3.18 -- PASSED
1st machine [USB 3.0] -- Linux 4.* -- FAILED

2nd machine [USB 2.0] -- Linux 4.0 -- PASSED

Therefore Jonah Hovold was right and root cause was underlying xhci driver.


2015-07-07 10:55 GMT+03:00 Johan Hovold <johan@xxxxxxxxxx>:
> On Mon, Jul 06, 2015 at 03:24:17PM +0200, Peter Stuge wrote:
>
>> Unrelated, but I also have some ch341 hardware, and mine does not
>> work with the mainline driver, it does however work reliably with the
>> vendor driver.
>>
>> The two drivers initialize the hardware fairly differently,
>> especially the baudrate generator, and the mainline driver doesn't
>> support all control signals and modes.
>>
>> A few things are obvious and easy for me to fix and post, but I'm not
>> sure how to proceed with the more complicated things; the baudrate
>> seems to have two settings, one clock divisor set on init and another
>> set depending on the selected baudrate. Mainline uses a different
>> algorithm to set these than the vendor driver.
>>
>> I notice that my hardware version is more recent than the mainline
>> driver was written for. I also notice that my hardware does not
>> respond according to the expectations documented in mainline
>> comments.
>>
>>
>> Your thoughts? I know that another person was also working on this.
>
> It should be possible to detect what version of the hardware is being
> used and switch baudrate-configuration scheme accordingly if necessary.
> Does anyone know how the vendor driver works with older devices?
>
> I've added Karl on CC who I think have been working on getting these new
> devices supported as well.
>
> Thanks,
> Johan
--
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



[Index of Archives]     [Linux Media]     [Linux Input]     [Linux Audio Users]     [Yosemite News]     [Linux Kernel]     [Linux SCSI]     [Old Linux USB Devel Archive]

  Powered by Linux