Re: Regarding USB-serial device driver

From: Raju Rameshwar Uprade
Date: Tue Sep 07 2010 - 23:41:32 EST




> Wierd. If you enable debugging in the driver:
> modprobe pl2303 debug=1
> do you also see the kernel log showing extra data going out to the host?
>
> What is your userspace program doing? Are you sure you are only writing
> 6 bytes? The bulk out should only be writing the actual data in the
> buffer, not any more than that.
>
> Do you have an example userspace code that we can use to test with?
>
> thanks,
>
> greg k-h

Greg,
I am really sorry, that superfluous data was due to user space program.I have
modified that.Now I am able to send correct data to the device. 5e and 40 is also going
out.I don't know from where it is coming.
But I am not getting the response.

output of usbmon :

ee9e1680 4108443204 C Co:7:003:0 0 0
f6e80c00 4108443237 S Bo:7:003:2 -115 9 = 05080000 00000000 f8 // correct data bytes
f6e80c00 4108444202 C Bo:7:003:2 0 9 >
ee9e1680 4108448251 S Co:7:003:0 s 21 22 0000 0000 0000 0
ee9e1680 4108449202 C Co:7:003:0 0 0
f6e80700 4108450204 C Bi:7:003:3 0 1 = 00
ee9e1680 4108450546 S Co:7:003:0 s 21 22 0003 0000 0000 0
f6e80900 4108451204 C Ii:7:003:1 0:1 10 = a1200000 00000200 0400
f6e80900 4108451223 S Ii:7:003:1 -115:1 10 <
ee9e1680 4108451227 C Co:7:003:0 0 0
f6e80c00 4108451252 S Bo:7:003:2 -115 1 = 5e // don't know from where it is going out
f6e80c00 4108452201 C Bo:7:003:2 0 1 >
f6e80900 4108453203 C Ii:7:003:1 0:1 10 = a1200000 00000200 0000
f6e80900 4108453221 S Ii:7:003:1 -115:1 10 <
ee9e1680 4108456262 S Co:7:003:0 s 21 22 0000 0000 0000 0
ee9e1680 4108457202 C Co:7:003:0 0 0
ee9e1680 4108457225 S Co:7:003:0 s 21 22 0003 0000 0000 0
ee9e1680 4108458201 C Co:7:003:0 0 0
f6e80c00 4108458228 S Bo:7:003:2 -115 1 = 40 // don't know from where it is going out
f6e80c00 4108459201 C Bo:7:003:2 0 1 >
ee9e1680 4108463235 S Co:7:003:0 s 21 22 0000 0000 0000 0
ee9e1680 4108464204 C Co:7:003:0 0 0

Regards,
Raj.

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