2008-12-21 03:30:11

by arrow.ebd

Subject: usb-serial: how to let ch341 work with baudrate 57600 ?

dear frank,

I have a USB-to-RS232 connector with chip ch341, but it
can not work under baud rate 57600.

I checked baud rate is set in function "ch341_set_baudrate".

How can I setup it with baudrate 57600 ?

I would like hear from you, Or give me some suggestion
to hack it.

Thanks

2008-12-21 14:19:20

by Matan Ziv-Av

Subject: Re: usb-serial: how to let ch341 work with baudrate 57600 ?

On Sun, 21 Dec 2008, [email protected] wrote:

> dear frank,
>
> I have a USB-to-RS232 connector with chip ch341, but it
> can not work under baud rate 57600.
>
> I checked baud rate is set in function "ch341_set_baudrate".
>
> How can I setup it with baudrate 57600 ?
>
> I would like hear from you, Or give me some suggestion
> to hack it.

See here: http://lkml.org/lkml/2008/9/21/17 for a patch that allows
arbitrary baud rate.


--
Matan Ziv-Av. [email protected]

2008-12-22 05:21:20

by arrow.ebd

Subject: Re: usb-serial: how to let ch341 work with baudrate 57600 ?

On Sun, Dec 21, 2008 at 04:19:01PM +0200, Matan Ziv-Av wrote:
> On Sun, 21 Dec 2008, [email protected] wrote:
>> dear frank,
>>
>> I have a USB-to-RS232 connector with chip ch341, but it
>> can not work under baud rate 57600.
>>
>> I checked baud rate is set in function "ch341_set_baudrate".
>>
>> How can I setup it with baudrate 57600 ?
>>
>> I would like hear from you, Or give me some suggestion
>> to hack it.
>
> See here: http://lkml.org/lkml/2008/9/21/17 for a patch that allows
> arbitrary baud rate.
> --
> Matan Ziv-Av. [email protected]

Thanks for your information, I have tried it, but can not work, dmesg
as below:(what should me to do)

[ 2416.718758] drivers/usb/serial/ch341.c: ch341_open()
[ 2416.718766] drivers/usb/serial/ch341.c: ch341_configure()
[ 2416.718774] drivers/usb/serial/ch341.c: ch341_control_in(c0,5f,0000,0000,f60f9838,8)
[ 2416.720055] drivers/usb/serial/ch341.c: ch341_control_out(40,a1,0000,0000)
[ 2416.721035] drivers/usb/serial/ch341.c: ch341_set_baudrate(2400)
[ 2416.721042] drivers/usb/serial/ch341.c: ch341_control_out(40,9a,1312,d901)
[ 2416.722028] drivers/usb/serial/ch341.c: ch341_control_out(40,9a,0f2c,0006)
[ 2416.723068] drivers/usb/serial/ch341.c: ch341_control_in(c0,95,2518,0000,f60f9838,8)
[ 2416.724035] drivers/usb/serial/ch341.c: ch341_control_out(40,9a,2518,0050)
[ 2416.725062] drivers/usb/serial/ch341.c: ch341_get_status()
[ 2416.725069] drivers/usb/serial/ch341.c: ch341_control_in(c0,95,0706,0000,f60f9840,8)
[ 2416.726030] drivers/usb/serial/ch341.c: ch341_control_out(40,a1,501f,d90a)
[ 2416.727114] drivers/usb/serial/ch341.c: ch341_set_baudrate(2400)
[ 2416.727121] drivers/usb/serial/ch341.c: ch341_control_out(40,9a,1312,d901)
[ 2416.727988] drivers/usb/serial/ch341.c: ch341_control_out(40,9a,0f2c,0006)
[ 2416.729062] drivers/usb/serial/ch341.c: ch341_set_handshake(0x60)
[ 2416.729068] drivers/usb/serial/ch341.c: ch341_control_out(40,a4,ff9f,0000)
[ 2416.730287] drivers/usb/serial/ch341.c: ch341_get_status()
[ 2416.730296] drivers/usb/serial/ch341.c: ch341_control_in(c0,95,0706,0000,f60f9840,8)
[ 2416.731064] drivers/usb/serial/ch341.c: ch341_set_handshake(0x60)
[ 2416.731070] drivers/usb/serial/ch341.c: ch341_control_out(40,a4,ff9f,0000)
[ 2416.732064] drivers/usb/serial/ch341.c: ch341_set_baudrate(2400)
[ 2416.732071] drivers/usb/serial/ch341.c: ch341_control_out(40,9a,1312,d901)
[ 2416.733063] drivers/usb/serial/ch341.c: ch341_control_out(40,9a,0f2c,0006)
[ 2416.734064] drivers/usb/serial/ch341.c: ch341_open - submitting interrupt urb
[ 2416.734071] ch341-uart ttyUSB0: ch341_open - failed submitting interrupt urb, error -2
[ 2416.734079] drivers/usb/serial/ch341.c: ch341_close - port 0
[ 2416.734084] drivers/usb/serial/ch341.c: ch341_close - shutting down urbs
[ 2416.734091] drivers/usb/serial/ch341.c: ch341_set_handshake(0x00)
[ 2416.734097] drivers/usb/serial/ch341.c: ch341_control_out(40,a4,ffff,0000)

I have checked the "erro -2" was occured at "usb_submit_urb" "return -ENOENT".