pyusb-users — PyUSB users mailing list discussion

Re: [Pyusb-users] Unknown error trying to getString from devices on OSX

[Yaniv A. <ya...@ak...>]

Hi Sarah,

Many thanks for your reply, which seems right on the money other than the
platform -- it's my understanding that your patch (and bug) occur only in
linux.c, while I'm running OSX and I believe my libusb uses darwin.c. From a
rather cursory examination it appears to me that the code in darwin.c is
substantially different (of course, different USB APIs in Linux and OSX),
and in particular the set-error-but-not-description bug doesn't appear to be
there.

Makes sense? Am I missing something? Anyone else has comments?

Thanks again,
 - Yaniv

On 10/21/07, Sarah Messer <iku...@ya...> wrote:
>
> This is due to a particular line in the source that sets an error-occurred
> flag but not the numerical error code itself.  I've tried posting analysis
> and solution here<http://forums.ni.com/ni/board/message?board.id=140&message.id=21028&view=by_date_ascending&page=2>
> (as user SMesser) and here<http://sourceforge.net/tracker/index.php?func=detail&aid=1633542&group_id=1674&atid=101674>(as user spinmess).  Look for the
> libusb.c patch I've posted.
>
> *Yaniv Aknin <ya...@ak...>* wrote:
>
> Hi,
>
> I'm trying to use PyUSB on OSX (10.4.10) to enumerate USB devices. I'm not
> entirely certain why, but upon calling getString on a device (almost any
> device on my system at least, and I have a few), I'm getting a USBError,
> with usb_control_msg: unknown error.
>
> My (slightly modified) lsusb.py source is:
>
> osx:pyusb yaniv$ cat lsusb.py
> #!/usr/bin/env python
>
> import usb
> import sys
>
> for bus in usb.busses():
>         for dev in bus.devices:
>                 try:
>                         print "Bus %s Device %s: ID %04x:%04x %s" % (
> bus.dirname,dev.filename,dev.idVendor,dev.idProduct,dev.open
> ().getString(1,30))
>                 except:
>                         print 'caught ', sys.exc_info()[1]
>                         continue
> osx:pyusb yaniv$ ./lsusb.py
> caught usb_control_msg(DeviceRequestTO): unknown error
> caught usb_control_msg(DeviceRequestTO): unknown error
> caught usb_control_msg(DeviceRequestTO): unknown error
> caught usb_control_msg(DeviceRequestTO): unknown error
> caught usb_control_msg(DeviceRequestTO): unknown error
> caught usb_control_msg(DeviceRequestTO): unknown error
> caught usb_control_msg(DeviceRequestTO): pipe is stalled
> caught usb_control_msg(DeviceRequestTO): pipe is stalled
> Bus 005 Device 002-05ac-8501-ff-ff: ID 05ac:8501 Micron
> caught usb_control_msg(DeviceRequestTO): pipe is stalled
> osx:pyusb yaniv$
>
> The exception is caught on the getString(), not on the open().
>
> I don't know what's special about this Micron device which works.
>
> I've tried running as UID 0 as well.
>
> Any further ideas?
>
> Many thanks,
>  - Yaniv
> -------------------------------------------------------------------------
> This SF.net email is sponsored by: Splunk Inc.
> Still grepping through log files to find problems? Stop.
> Now Search log events and configuration files using AJAX and a browser.
> Download your FREE copy of Splunk now >>
> http://get.splunk.com/_______________________________________________
> Pyusb-users mailing list
> Pyu...@li...
> https://lists.sourceforge.net/lists/listinfo/pyusb-users
>
>
>
>
> -Sarah
>
> __________________________________________________
> Do You Yahoo!?
> Tired of spam? Yahoo! Mail has the best spam protection around
> http://mail.yahoo.com
>

Re: [Pyusb-users] Unknown error trying to getString from devices on OSX

[Sarah M. <iku...@ya...>]

This is due to a particular line in the source that sets an error-occurred flag but not the numerical error code itself.  I've tried posting analysis and solution here
(as user SMesser) and here (as user spinmess).  Look for the libusb.c patch I've posted.

Yaniv Aknin <ya...@ak...> wrote: Hi,

I'm trying to use PyUSB on OSX (10.4.10) to enumerate USB devices. I'm not entirely certain why, but upon calling getString on a device (almost any device on my system at least, and I have a few), I'm getting a USBError, with usb_control_msg: unknown error. 

My (slightly modified) lsusb.py source is:

osx:pyusb yaniv$ cat lsusb.py 
#!/usr/bin/env python
 
import usb
import sys
 
for bus in usb.busses():
        for dev in bus.devices:
                try: 
                        print "Bus %s Device %s: ID %04x:%04x %s" % (bus.dirname,dev.filename,dev.idVendor,dev.idProduct,dev.open().getString(1,30))
                except:
                        print 'caught ',  sys.exc_info()[1]
                        continue
osx:pyusb yaniv$ ./lsusb.py 
caught usb_control_msg(DeviceRequestTO): unknown error
caught usb_control_msg(DeviceRequestTO): unknown error
caught usb_control_msg(DeviceRequestTO): unknown error 
caught usb_control_msg(DeviceRequestTO): unknown error
caught usb_control_msg(DeviceRequestTO): unknown error
caught usb_control_msg(DeviceRequestTO): unknown error
caught usb_control_msg(DeviceRequestTO): pipe is stalled 
caught usb_control_msg(DeviceRequestTO): pipe is stalled
Bus 005 Device 002-05ac-8501-ff-ff: ID 05ac:8501 Micron
caught usb_control_msg(DeviceRequestTO): pipe is stalled
osx:pyusb yaniv$ 

The exception is caught on the getString(), not on the open(). 

I don't know what's special about this Micron device which works.

I've tried running as UID 0 as well.

Any further ideas?

Many thanks,
 - Yaniv
 -------------------------------------------------------------------------
This SF.net email is sponsored by: Splunk Inc.
Still grepping through log files to find problems?  Stop.
Now Search log events and configuration files using AJAX and a browser.
Download your FREE copy of Splunk now >> http://get.splunk.com/_______________________________________________
Pyusb-users mailing list
Pyu...@li...
https://lists.sourceforge.net/lists/listinfo/pyusb-users



-Sarah
 __________________________________________________
Do You Yahoo!?
Tired of spam?  Yahoo! Mail has the best spam protection around 
http://mail.yahoo.com 

[Pyusb-users] Unknown error trying to getString from devices on OSX

[Yaniv A. <ya...@ak...>]

Hi,

I'm trying to use PyUSB on OSX (10.4.10) to enumerate USB devices. I'm not
entirely certain why, but upon calling getString on a device (almost any
device on my system at least, and I have a few), I'm getting a USBError,
with usb_control_msg: unknown error.

My (slightly modified) lsusb.py source is:

osx:pyusb yaniv$ cat lsusb.py
#!/usr/bin/env python

import usb
import sys

for bus in usb.busses():
        for dev in bus.devices:
                try:
                        print "Bus %s Device %s: ID %04x:%04x %s" % (
bus.dirname,dev.filename,dev.idVendor,dev.idProduct,dev.open
().getString(1,30))
                except:
                        print 'caught ', sys.exc_info()[1]
                        continue
osx:pyusb yaniv$ ./lsusb.py
caught usb_control_msg(DeviceRequestTO): unknown error
caught usb_control_msg(DeviceRequestTO): unknown error
caught usb_control_msg(DeviceRequestTO): unknown error
caught usb_control_msg(DeviceRequestTO): unknown error
caught usb_control_msg(DeviceRequestTO): unknown error
caught usb_control_msg(DeviceRequestTO): unknown error
caught usb_control_msg(DeviceRequestTO): pipe is stalled
caught usb_control_msg(DeviceRequestTO): pipe is stalled
Bus 005 Device 002-05ac-8501-ff-ff: ID 05ac:8501 Micron
caught usb_control_msg(DeviceRequestTO): pipe is stalled
osx:pyusb yaniv$

The exception is caught on the getString(), not on the open().

I don't know what's special about this Micron device which works.

I've tried running as UID 0 as well.

Any further ideas?

Many thanks,
 - Yaniv

[Pyusb-users] open device handle requires root access

[<Dan...@we...>]

Hi,

I have read the recent post about how to create a udev rule for a specific usb device in order to change its access rights, however, I have still trouble getting access to it without being root.

This is what I did.

Following the explanation here:

http://www.reactivated.net/writing_udev_rules.html

I plugged the device in and checked dmesg

--> usb 4-2: new high speed USB device using ehci_hcd and address 7

So I called now udevinfo:

> udevinfo -a -p /sys/bus/usb/devices/usb4/4-2/

and got this:

looking at class device '/sys/bus/usb/devices/usb4/4-2':
    KERNEL=="4-2"
    SUBSYSTEM=="unknown"
    SYSFS{bConfigurationValue}=="1"
    SYSFS{bDeviceClass}=="00"
    SYSFS{bDeviceProtocol}=="00"
    SYSFS{bDeviceSubClass}=="00"
    SYSFS{bMaxPacketSize0}=="64"
    SYSFS{bMaxPower}=="  0mA"
    SYSFS{bNumConfigurations}=="1"
    SYSFS{bNumInterfaces}==" 1"
    SYSFS{bcdDevice}=="0000"
    SYSFS{bmAttributes}=="40"
    SYSFS{configuration}==""
    SYSFS{devnum}=="7"
    SYSFS{idProduct}=="0003"
    SYSFS{idVendor}=="1443"
    SYSFS{manufacturer}=="Digilent"
    SYSFS{maxchild}=="0"
    SYSFS{product}=="USB Module"
    SYSFS{speed}=="480"
    SYSFS{version}==" 2.00"

What is strange about this is that the subsystem is set to unknown. Anyway, based on the explanation I should create the rule  based on the previous information and this is what I did:

    KERNEL=="4-2",SYSFS{idVendor}=="1443",SYSFS{idProduct}=="0003",GROUP="users",MODE="0660"

Added the rule to the 10-local.rules file in the /etc/udev/rules.d folder and called udevstart.

I am still cannot call my PyUsb program to open the device under my user name, who is part of the "users" group.

Am I doing something wrong here?

I am using PyUsb 0.4.0 with libusb 0.1.10a, linux kernel 2.6.13-15.16-default

Thanks for any help.

Cheers,

Guenter




_____________________________________________________________________
Der WEB.DE SmartSurfer hilft bis zu 70% Ihrer Onlinekosten zu sparen!
http://smartsurfer.web.de/?mc=100071&distributionid=000000000066

[Pyusb-users] device or resource busy

[<dai...@al...>]

hello,
while running this program (from the README file, into the package =
pyusb-0.3.5)..

#____program____


import usb                 # import the usb module



bus =3D usb.busses()         # get a list of all available busses



dev =3D bus[4].devices[0]    # choose the first device on the first bus



handle =3D dev.open()        # open the device



for alt in dev.configurations[0].interfaces[0]:

    print alt              # look at the alternate settings.



handle.setConfiguration(0) # choose the first configuration



handle.claimInterface(0)   # choose the first interface



### Use the device here. ###



handle.releaseInterface()  # also called automatically on __del__



#____end____

..i got the following error:

Traceback (most recent call last):
  File "progreadme.py", line 13, in ?
    handle.setConfiguration(0) # choose the first configuration
usb.USBError: could not set config 0: Device or resource busy

every bus number i fill in, i got the error, and if i comment the error =
line, error in the next line: still "device or resource busy".
i have to run it as a Super User, or i'm told "operation not permitted", =
but i think that's normal.
can someone help me?
i'm using debian 4.0 etch
 thank you -and sorry for my bad english-
  stefano

Re: [Pyusb-users] USB control requires root access

[Andrew S. <str...@as...>]

Sarah,

I think the simplest way is to go through udev.

1) create a group named something like "tekscope"

2) Create a file in /etc/udev/rules.d (well, that's where it is on 
Ubuntu) something like:

SUBSYSTEM=="usb_device", ACTION=="add", SYSFS{idVendor}=="1234",
SYSFS{idProduct}=="5678", GROUP="tekscope", MODE="0660"

3) Restart udev to re-load the new rules, and voila, anyone in the 
tekscope group should be able to access the USB device created when the 
device is plugged in.

Sarah Messer wrote:
> Hello,
>
> I have a (working) USB interface to a Tektronix TDS-2014B oscilloscope 
> based around pyusb.  My issue is that it's only usable when I'm 
> SuperUser.  I'm doing support work for a company, and would rather not 
> require several different people to log in as root in order to 
> download data from the scopes.  Here's what I've figured out so far:
>
> 1)  The following python commands work the way one would expect if 
> logged in as root:
> > import usb
> > barn=usb.busses()
> >barn[1].devices
> (<usb.Device object at 0x80ee5f8>,)
>
> 2)  If I lack root access, the device list returns empty:
> ()
>
> 3)  I'm running SuSe 10.0 with python 2.4.1, pyusb 0.3.5, and 
> libusb-0.1.12 (with a minimal custom patch, see my posting on the 
> libusb group 
> <http://sourceforge.net/tracker/index.php?func=detail&aid=1633542&group_id=1674&atid=101674> 
> for details).
>
> If I understand things correctly, there are three different low-level 
> daemons / drivers which might be involved in establishing permissions 
> for the USB ports: HAL, udev, and hotplug.  I seem to have bits of all 
> three on the system, and I'm trying to figure out which one sets the 
> permissions:
>
> Things I've tried:
> 1) editted fstab to put the "users,dev,exec" flags on the usbfs line 
> (in addition to the "noauto" flag that was there already.  The full 
> listing is:
> usbfs   /proc/bus/usb   usbfs   noauto,users,dev,exec   0   0
> Despite this, rebooting mounts the usbfs with only the rw flag, not 
> the users flag and so on.  This makes me think that fstab doesn't 
> actually control mounting of usbfs.
> 2)  I tried editting the mount commands in /etc/hotplug/usb.rc, but 
> again this has no effect.  I made the first line of this file
> echo "Executing /etc/hotplug/usb.rc \a"
> but rebooting doesn't seem to produce either the bell or message.  
> This makes me think Hotplug isn't handling the USB communication either.
> 3)  lsmod and ps reveal the following potentially-relevant modules / 
> processes:  pci_hotplug, usblp, usbcore, ehci_hcd, uhci_hcd, hald, 
> hald-addon-acpi, hald-addon-stor, and udevd.
> 4)  If I run "chgrp users /dev/usbdev*" (as root), the affected 
> devices become available to non-root users.  However, if a device (or 
> the PC) is power-cycled, it becomes root-only again.
>
> Any ideas on how to tell whether I need to learn HAL or UDev or 
> something else?  Any clues on how to let pyusb talk to the scopes for 
> regular users?
>
> Thanks.
>
>
> -Sarah
>
> ------------------------------------------------------------------------
> Ahhh...imagining that irresistible "new car" smell?
> Check out new cars at Yahoo! Autos. 
> <http://us.rd.yahoo.com/evt=48245/*http://autos.yahoo.com/new_cars.html;_ylc=X3oDMTE1YW1jcXJ2BF9TAzk3MTA3MDc2BHNlYwNtYWlsdGFncwRzbGsDbmV3LWNhcnM-> 
>
> ------------------------------------------------------------------------
>
> -------------------------------------------------------------------------
> This SF.net email is sponsored by DB2 Express
> Download DB2 Express C - the FREE version of DB2 express and take
> control of your XML. No limits. Just data. Click to get it now.
> http://sourceforge.net/powerbar/db2/
> ------------------------------------------------------------------------
>
> _______________________________________________
> Pyusb-users mailing list
> Pyu...@li...
> https://lists.sourceforge.net/lists/listinfo/pyusb-users
>   

[Pyusb-users] USB control requires root access

[Sarah M. <iku...@ya...>]

Hello,

I have a (working) USB interface to a Tektronix TDS-2014B oscilloscope based around pyusb.  My issue is that it's only usable when I'm SuperUser.  I'm doing support work for a company, and would rather not require several different people to log in as root in order to download data from the scopes.  Here's what I've figured out so far:

1)  The following python commands work the way one would expect if logged in as root:
> import usb
> barn=usb.busses()
>barn[1].devices
(<usb.Device object at 0x80ee5f8>,)

2)  If I lack root access, the device list returns empty:
()

3)  I'm running SuSe 10.0 with python 2.4.1, pyusb 0.3.5, and libusb-0.1.12 (with a minimal custom patch, see my posting on the libusb group for details).

If I understand things correctly, there are three different low-level daemons / drivers which might be involved in establishing permissions for the USB ports: HAL, udev, and hotplug.  I seem to have bits of all three on the system, and I'm trying to figure out which one sets the permissions:

Things I've tried:
1) editted fstab to put the "users,dev,exec" flags on the usbfs line (in addition to the "noauto" flag that was there already.  The full listing is:
usbfs   /proc/bus/usb   usbfs   noauto,users,dev,exec   0   0
Despite this, rebooting mounts the usbfs with only the rw flag, not the users flag and so on.  This makes me think that fstab doesn't actually control mounting of usbfs.
2)  I tried editting the mount commands in /etc/hotplug/usb.rc, but again this has no effect.  I made the first line of this file 
echo "Executing /etc/hotplug/usb.rc \a"
but rebooting doesn't seem to produce either the bell or message.  This makes me think Hotplug isn't handling the USB communication either.
3)  lsmod and ps reveal the following potentially-relevant modules / processes:  pci_hotplug, usblp, usbcore, ehci_hcd, uhci_hcd, hald, hald-addon-acpi, hald-addon-stor, and udevd.
4)  If I run "chgrp users /dev/usbdev*" (as root), the affected devices become available to non-root users.  However, if a device (or the PC) is power-cycled, it becomes root-only again.

Any ideas on how to tell whether I need to learn HAL or UDev or something else?  Any clues on how to let pyusb talk to the scopes for regular users?

Thanks.


-Sarah
       
---------------------------------
Ahhh...imagining that irresistible "new car" smell?
 Check outnew cars at Yahoo! Autos.

Re: [Pyusb-users] pyusb interrupt transfers & threading

[Wander L. <wan...@gm...>]

Hi Christian,

I haven't tested PyUSB in a multi-thread environment yet, but you could try
run your script with python interpreter running into gdb, so you can stop it
and see
traceback to find out where the program is stalling...

Wander

PS: I have a little test board to PyUSB, so I think that I could use it
to test your code..

2006/8/23, Christian Niessner <ma...@ma...>:
>
> Hi list,
>
> I currently have a problem with threading & pyusb interrupt read
> transfers.
>
> My testapp has a thread that 'polls for interrupts' (ahem. but seems a
> libusb issue ;)). The mainapp only does some tests with the USB-device.
> Simple 'Hello World' things.
>
> It works so far except one thing: every time i call time.sleep() in the
> main app / main thread, and the poll thread waits for an
> interruptRead(), the time.sleep() never ever returns. Uh. Bad thing.
>
> Any ideas? I could send my code, but i think it's quite useless without
> the proper usb hardware....
>
> I tracked the problem a bit, and it seems to be connected to the
> interruptRead() call. If this call is replaced with a simple
> time.sleep(), the time.sleep() from the main thread works as expected...
>
> Any hints where digging / continuing ?
>
> Thanks,
>         chris
>
>
> -------------------------------------------------------------------------
> Using Tomcat but need to do more? Need to support web services, security?
> Get stuff done quickly with pre-integrated technology to make your job
> easier
> Download IBM WebSphere Application Server v.1.0.1 based on Apache Geronimo
> http://sel.as-us.falkag.net/sel?cmd=lnk&kid=120709&bid=263057&dat=121642
> _______________________________________________
> Pyusb-users mailing list
> Pyu...@li...
> https://lists.sourceforge.net/lists/listinfo/pyusb-users
>

[Pyusb-users] pyusb interrupt transfers & threading

[Christian N. <ma...@ma...>]

Hi list,

I currently have a problem with threading & pyusb interrupt read
transfers.

My testapp has a thread that 'polls for interrupts' (ahem. but seems a
libusb issue ;)). The mainapp only does some tests with the USB-device.
Simple 'Hello World' things.

It works so far except one thing: every time i call time.sleep() in the
main app / main thread, and the poll thread waits for an
interruptRead(), the time.sleep() never ever returns. Uh. Bad thing.

Any ideas? I could send my code, but i think it's quite useless without
the proper usb hardware....

I tracked the problem a bit, and it seems to be connected to the
interruptRead() call. If this call is replaced with a simple
time.sleep(), the time.sleep() from the main thread works as expected...

Any hints where digging / continuing ?

Thanks,
	chris

Re: [Pyusb-users] Bus Error

[Wander L. <wan...@gm...>]

Hi,

Sorry for the delay, could put here the output showded when you try run it?

Wander

[Pyusb-users] confirm 9d31322d37cedd0d2547abe85b60c96aa5953a10

[setoy s. <se...@ra...>]

--
setoy seth.

[Pyusb-users] Bus Errors

[Rod <use...@ya...>]

Hi,

I recently managed to compile both libusb and pyusb on
an Intel based Mac. However when I attempt to run any
PyUSB program I receive a bus error. This applies to
the example code or even to two line programs.

Can anyone provice me with assistance?

Best,

rod