Digging deeper with the help of usbmon I found that the driver
actually starts a USB "conversation" but blocks before sending the usb
bulk transfer down the wire.
Just in case someone is interested in following this issue (appart of
me ;) ) I send attached the usbmon output comparing the working/non
working kernel.
Enrique
On Fri, Dec 10, 2010 at 9:58 AM, ENRIQUE ARIZON BENITO
<enrique.arizonbenito@xxxxxxxxx> wrote:
> On Thu, Dec 9, 2010 at 11:30 PM, Matthew Dharm
> <mdharm-usb@xxxxxxxxxxxxxxxxxx> wrote:
>> On Thu, Dec 09, 2010 at 10:45:13PM +0100, ENRIQUE ARIZON BENITO wrote:
>>> A simple script like:
>>>
>>> echo "1" > /dev/ttyUSB0
>>>
>>> stopped to work after upgrading my system to a custom compiled version
>>> of kernel 2.6.35.
>>>
>>> There are no errors in syslog or dmesg and the pl2303 loads without
>>> complains, but strace shows that
>>> open("/dev/ttyUSB0",...) blocks forever.
>>>
>>> I guess it must be some wrong parameter in the compilation, but I'm
>>> blind trying to find the solution.
>>
>> Have you used stty to check the port mode settings? ÂIt may be blocking for
>> carrier detect....
>>
>> Matt
>>
>
> Yes, I did. In fact the setting as displayed from the output command
> "stty -a -F /dev/ttyUSB0" are equals both for the working kernel and
> the new (non working) one.
>
> Enrique
>
TEST COMMAND: echo "ka 0 0" > /dev/ttyUSB0
========================================================================================================================================================
|NEW KERNEL 2.6.35 | OLD KERNEL 2.6.30 (works OK) |
|STATUS: - block indefinitely | STATUS: OK |
| - no bulk transfer | |
| | |
|USBMON OUTPUT: | USBMON OUTPUT: |
|d703d440 195665928 S Co:2:004:0 s 40 01 0008 0000 0000 0 | d08932c0 485888870 S Co:2:002:0 s 40 01 0008 0000 0000 0 |
|d703d440 195667144 C Co:2:004:0 0 0 | d08932c0 485890422 C Co:2:002:0 0 0 |
|d703d440 195667179 S Co:2:004:0 s 40 01 0009 0000 0000 0 | d08932c0 485890442 S Co:2:002:0 s 40 01 0009 0000 0000 0 |
|d703d440 195668135 C Co:2:004:0 0 0 | d08932c0 485891416 C Co:2:002:0 0 0 |
|d703d440 195668164 S Ci:2:004:0 s a1 21 0000 0000 0007 7 < | d08932c0 485891432 S Ci:2:002:0 s a1 21 0000 0000 0007 7 < |
|d703d440 195669139 C Ci:2:004:0 0 7 = 80250000 000008 | d08932c0 485892416 C Ci:2:002:0 0 7 = 80250000 000008 |
|d703d440 195672227 S Co:2:004:0 s 21 20 0000 0000 0007 7 = 80250000 000008| d08932c0 485892430 S Co:2:002:0 s 21 20 0000 0000 0007 7 = 80250000 000008|
|d703d440 195673137 C Co:2:004:0 0 7 > | d08932c0 485893416 C Co:2:002:0 0 7 > |
|d703d440 195673172 S Co:2:004:0 s 21 22 0003 0000 0000 0 | d08932c0 485893429 S Co:2:002:0 s 21 22 0003 0000 0000 0 |
|d703d440 195674137 C Co:2:004:0 0 0 | d08932c0 485894416 C Co:2:002:0 0 0 |
|d703d440 195674174 S Ci:2:004:0 s a1 21 0000 0000 0007 7 < | d08932c0 485894428 S Ci:2:002:0 s a1 21 0000 0000 0007 7 < |
|d703d440 195675136 C Ci:2:004:0 0 7 = 80250000 000008 | d08932c0 485895416 C Ci:2:002:0 0 7 = 80250000 000008 |
|d703d440 195675175 S Co:2:004:0 s 40 01 0000 0000 0000 0 | d08932c0 485895429 S Co:2:002:0 s 40 01 0000 0000 0000 0 |
|d703d440 195676141 C Co:2:004:0 0 0 | d08932c0 485896415 C Co:2:002:0 0 0 |
|db17c740 195676190 S Bi:2:004:3 -115 256 < | dba00840 485896430 S Bi:2:002:3 -115 64 < |
|db17c440 195676200 S Ii:2:004:1 -115:1 10 < | dba007c0 485896435 S Ii:2:002:1 -115:1 10 < |
|d703d440 195676211 S Co:2:004:0 s 21 22 0003 0000 0000 0 | dba00b40 485896516 S Bo:2:002:2 -115 6 = 6b612030 2030 |
|d703d440 195677137 C Co:2:004:0 0 0 | dba00b40 485897422 C Bo:2:002:2 0 6 > |
|("HERE" USBMON STOP PRINTING DATA UNTIL PRESSING CTRL+C) | dba00b40 485897428 S Bo:2:002:2 -115 2 = 0d0a |
| | dba00b40 485898417 C Bo:2:002:2 0 2 > |
| | dba00840 486164411 C Bi:2:002:3 -2 0 |
| | dba007c0 486165412 C Ii:2:002:1 -2:1 0 |
|(OUTPUT AFTER PRESSING Ctrl+C) | d08932c0 486165431 S Co:2:002:0 s 21 22 0000 0000 0000 0 |
|d703d6c0 200802227 S Co:2:004:0 s 21 22 0003 0000 0000 0 | d08932c0 486166412 C Co:2:002:0 0 0 |
|d703d6c0 200804065 C Co:2:004:0 0 0 | |
|d703d6c0 200804122 S Co:2:004:0 s 21 22 0000 0000 0000 0 | |
|d703d6c0 200805060 C Co:2:004:0 0 0 | |
|db17c740 200806062 C Bi:2:004:3 -2 0 | |
|db17c440 200807058 C Ii:2:004:1 -2:1 0 | |
========================================================================================================================================================
