Automatic Activation, Hotplug and UDEV, Configuration
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rifo
Posts: 6
Joined: 11 Jan 2013, 17:06

missin ttyUSB* after usb_switchmode

Post by rifo » 11 Jan 2013, 17:30

Hello all,

I have a Vodafone K3770 dongle which I am trying to integrate to an embedded linux system running an ARM. I have taken the usb_switchmode from buildroot

Code: Select all

 
 * usb_modeswitch: handle USB devices with multiple modes
 * Version 1.2.5 (C) Josua Dietze 2012
 * Based on libusb0 (0.1.12 and above)

 ! PLEASE REPORT NEW CONFIGURATIONS !  
I have prepared a conf file as below

Code: Select all


#####################################
# Huawei, newer modems
DisableSwitching=0
EnableLoggin=1
#HuaweiMode=1
#DetachStorageOnly=1
DefaultVendor=0x12d1
DefaultProduct=0x14d1

TargetVendor=0x12d1
TargetProduct=0x1c05

CheckSuccess=20

MessageContent="55534243123456780000000000000011060000000000000000000000000000"

Currently I implement everything manually.

Code: Select all


# mount usbfs -t usbfs /proc/bus/usb/
# insmod ./usbserial.ko vendor=0x12d1 product=0x1c05
# ./usb_modeswitch -W -c ./usb_modeswitch.conf 

Once I run usb_modeswitch, here is the log output that I get

Code: Select all


Reading config file: ./usb_modeswitch.conf

 * usb_modeswitch: handle USB devices with multiple modes
 * Version 1.2.5 (C) Josua Dietze 2012
 * Based on libusb0 (0.1.12 and above)

 ! PLEASE REPORT NEW CONFIGURATIONS !

DefaultVendor=  0x12d1
DefaultProduct= 0x14d1
TargetVendor=   0x12d1
TargetProduct=  0x1c05
TargetClass=    not set
TargetProductList=""

DetachStorageOnly=0
HuaweiMode=0
SierraMode=0
SonyMode=0
QisdaMode=0
GCTMode=0
KobilMode=0
SequansMode=0
MobileActionMode=0
CiscoMode=0
MessageEndpoint=  not set
MessageContent="55534243123456780000000000000011060000000000000000000000000000"
NeedResponse=0
ResponseEndpoint= not set

InquireDevice enabled (default)
Success check enabled, max. wait time 20 seconds
System integration mode disabled


Looking for target devices ...
  searching devices, found USB ID 1d6b:0002
  searching devices, found USB ID 12d1:14d1
   found matching vendor ID
  searching devices, found USB ID 1d6b:0002
  searching devices, found USB ID 0424:2517
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 0bda:8176
 No devices in target mode or class found
Looking for default devices ...
  searching devices, found USB ID 1d6b:0002
  searching devices, found USB ID 12d1:14d1
   found matching vendor ID
   found matching product ID
   adding device
  searching devices, found USB ID 1d6b:0002
  searching devices, found USB ID 0424:2517
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 0bda:8176
 Found device in default mode, class or configuration (1)
Accessing device 002 on bus 001 ...
Getting the current device configuration ...
 OK, got current device configuration (1)
Using interface number 0
Using endpoints 0x0f (out) and 0x8f (in)
Inquiring device details; driver will be detached ...
Looking for active driver ...
 OK, driver found; name unknown, limitation of libusb1
 OK, driver "unkown" detached

SCSI inquiry data (for identification)
-------------------------
  Vendor String: Vodafone
   Model String: CD ROM (Huawei) 
Revision String: 2.31
-------------------------

USB description data (for identification)
-------------------------
Manufacturer: HUAWEI
     Product: Vodafone Mobile Broadband (Huawei)
  Serial No.: not provided
-------------------------
Setting up communication with interface 0
Using endpoint 0x0f for message sending ...
Trying to send message 1 to endpoint 0x0f ...
 OK, message successfully sent
Resetting response endpoint 0x8f
libusb:error [op_clear_halt] clear_halt failed error -1 errno 71
 Could not reset endpoint (probably harmless): -34
Resetting message endpoint 0x0f
 Could not reset endpoint (probably harmless): -6
 Device is gone, skipping any further commands

Checking for mode switch (max. 20 times, once per second) ...
 Searching for target devices ...
  searching devices, found USB ID 1d6b:0002
  searching devices, found USB ID 1d6b:0002
  searching devices, found USB ID 0424:2517
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 0bda:8176
 Searching for target devices ...
  searching devices, found USB ID 1d6b:0002
  searching devices, found USB ID 1d6b:0002
  searching devices, found USB ID 0424:2517
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 0bda:8176
 Searching for target devices ...
  searching devices, found USB ID 12d1:1c05
   found matching vendor ID
   found matching product ID
   adding device
  searching devices, found USB ID 1d6b:0002
  searching devices, found USB ID 1d6b:0002
  searching devices, found USB ID 0424:2517
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 0bda:8176

Found target device, now opening

Found target device 003 on bus 001

Target device description data
-------------------------
Manufacturer: HUAWEI
     Product: Vodafone Mobile Broadband (Huawei)
  Serial No.: not provided
-------------------------
 Found correct target device

Mode switch succeeded. Bye.



I can see that the switching operation is successful

Code: Select all

# lsusb
Bus 001 Device 003: ID 12d1:1c05
However no ttyUSB* files are generated under /dev folder.

Can you please guide me about this problem?

Thanks a lot in advance for your help.
Rifat

Josh
Site Admin
Posts: 6593
Joined: 03 Nov 2007, 00:30

Re: missin ttyUSB* after usb_switchmode

Post by Josh » 12 Jan 2013, 09:55

You need to bind the modem port driver ("option") to the device after the mode switch:

Code: Select all

# modprobe -v option
# echo "12d1 1c05" > /sys/bus/usb-serial/drivers/option1/new_id
The full usb_modeswitch package does this automatically; if you have "udev" running on your system, consider using it.

rifo
Posts: 6
Joined: 11 Jan 2013, 17:06

Re: missin ttyUSB* after usb_switchmode

Post by rifo » 14 Jan 2013, 17:35

Hello,

Thanks a lot for your answer. I have tried implementing your suggestions but came across a couple of problems. Here is what I did

Code: Select all

# mount usbfs -t usbfs /proc/bus/usb
# ./usb_modeswitch -W -c ./usb_modeswitch.conf

          * usb_modeswitch: handle USB devices with multiple modes
 * Version 1.2.5 (C) Josua Dietze 2012
 * Based on libusb0 (0.1.12 and above)

 ! PLEASE REPORT NEW CONFIGURATIONS !

DefaultVendor=  0x12d1
DefaultProduct= 0x14d1
TargetVendor=   0x12d1
TargetProduct=  0x1c05
TargetClass=    not set
TargetProductList=""

DetachStorageOnly=0
HuaweiMode=0
SierraMode=0
SonyMode=0
QisdaMode=0
GCTMode=0
KobilMode=0
SequansMode=0
MobileActionMode=0
CiscoMode=0
MessageEndpoint=  not set
MessageContent="55534243123456780000000000000011060000000000000000000000000000"
NeedResponse=0
ResponseEndpoint= not set

InquireDevice enabled (default)
Success check enabled, max. wait time 20 seconds
System integration mode disabled


Looking for target devices ...
  searching devices, found USB ID 1d6b:0002
  searching devices, found USB ID 12d1:14d1
   found matching vendor ID
  searching devices, found USB ID 1d6b:0002
  searching devices, found USB ID 0424:2517
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
 No devices in target mode or class found
Looking for default devices ...
  searching devices, found USB ID 1d6b:0002
  searching devices, found USB ID 12d1:14d1
   found matching vendor ID
   found matching product ID
   adding device
  searching devices, found USB ID 1d6b:0002
  searching devices, found USB ID 0424:2517
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
 Found device in default mode, class or configuration (1)
Accessing device 002 on bus 001 ...
Getting the current device configuration ...
 OK, got current device configuration (1)
Using interface number 0
Using endpoints 0x0f (out) and 0x8f (in)
Inquiring device details; driver will be detached ...
Looking for active driver ...
 OK, driver found; name unknown, limitation of libusb1
 OK, driver "unkown" detached

SCSI inquiry data (for identification)
-------------------------
  Vendor String: Vodafone
   Model String: CD ROM (Huawei) 
Revision String: 2.31
-------------------------

USB description data (for identification)
-------------------------
Manufacturer: HUAWEI
     Product: Vodafone Mobile Broadband (Huawei)
  Serial No.: not provided
-------------------------
Setting up communication with interface 0
Using endpoint 0x0f for message sending ...
Trying to send message 1 to endpoint 0x0f ...
 OK, message successfully sent
Resetting response endpoint 0x8f
libusb:error [op_clear_halt] clear_halt failed error -1 errno 71
 Could not reset endpoint (probably harmless): -99
Resetting message endpoint 0x0f
 Could not reset endpoint (probably harmless): -4
 Device is gone, skipping any further commands

Checking for mode switch (max. 20 times, once per second) ...
 Searching for target devices ...
  searching devices, found USB ID 1d6b:0002
  searching devices, found USB ID 1d6b:0002
  searching devices, found USB ID 0424:2517
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
 Searching for target devices ...
  searching devices, found USB ID 1d6b:0002
  searching devices, found USB ID 1d6b:0002
  searching devices, found USB ID 0424:2517
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
 Searching for target devices ...
  searching devices, found USB ID 12d1:1c05
   found matching vendor ID
   found matching product ID
   adding device
  searching devices, found USB ID 1d6b:0002
  searching devices, found USB ID 1d6b:0002
  searching devices, found USB ID 0424:2517
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3
  searching devices, found USB ID 1199:68a3

Found target device, now opening

Found target device 003 on bus 001

Target device description data
-------------------------
Manufacturer: HUAWEI
     Product: Vodafone Mobile Broadband (Huawei)
  Serial No.: not provided
-------------------------
 Found correct target device

Mode switch succeeded. Bye.

Code: Select all

# lsusb
...
Bus 001 Device 003: ID 12d1:1c05
...

Later on, I have tried making use of modprobe but got the following problem so I kept relying on insmod

Code: Select all

Could not load /lib/modules/2.6.32_V3_HDMI/modules.deb
I also had some problems making use of the "new_id" mechansim in /sys/bus/... so I tried passing parameters to option.ko to no avail

Code: Select all

insmod ./usbserial.ko 
# insmod ./option.ko vendor=0x12d1 product=0x1c05
insmod: can't insert './option.ko': unknown symbol in module, or unknown parameter
# insmod ./option.ko  
At this point, I guess that option.ko cannot know that 0x1c05 is its target. Below is the reason that I believe new_id is not available on my kernel

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# cat /sys/bus/usb-serial/drivers/option1/new_id               
cat: can't open '/sys/bus/usb-serial/drivers/option1/new_id': Permission denied

ls /dev/ttyUSB* doesn't show any output

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# ls /dev/ttyUSB*
ls: /dev/ttyUSB*: No such file or directory

My kernel version is

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# uname -r
2.6.32_V3_HDMI

I have searched through the forum and came across a post where you suggested modifying the option.c source code when "new_id" mechanism doesn't work. I updated option.c such that there is an

++ #define HUAWEI_PRODUCT_E1C05 0x1C05

++ { USB_DEVICE(HUAWEI_VENDOR_ID, HUAWEI_PRODUCT_E1C05) },

Note that I have also tried adding the second line like below to no avail
++ { USB_DEVICE_AND_INTERFACE_INFO(HUAWEI_VENDOR_ID, HUAWEI_PRODUCT_E1C05, 0xff, 0xff, 0xff) },

I have then compiled this module and loaded that to the embedded linux system of mine but the driver didn't get the modem. Below is the last lines of my dmesg output

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[ 4577.249053] usb 1-1: USB disconnect, address 2
[ 4579.653900] usb 1-1: new high speed USB device using musb_hdrc and address 3
[ 4579.803375] usb 1-1: New USB device found, idVendor=12d1, idProduct=1c05
[ 4579.803405] usb 1-1: New USB device strings: Mfr=2, Product=1, SerialNumber=0
[ 4579.803405] usb 1-1: Product: Vodafone Mobile Broadband (Huawei)
[ 4579.803436] usb 1-1: Manufacturer: HUAWEI
[ 4579.806030] usb 1-1: no configuration chosen from 1 choice

[ 5137.920776] option: Unknown symbol usb_serial_port_softint
[ 5137.923583] option: Unknown symbol usb_serial_disconnect
[ 5137.925140] option: Unknown symbol usb_serial_suspend
[ 5137.931365] option: Unknown symbol usb_serial_probe
[ 5137.931915] option: Unknown symbol usb_serial_register
[ 5137.932312] option: Unknown symbol usb_serial_deregister
[ 5137.932708] option: Unknown symbol usb_serial_resume
[ 5156.630401] usbcore: registered new interface driver usbserial
[ 5156.631744] USB Serial support registered for generic
[ 5156.648040] usbcore: registered new interface driver usbserial_generic
[ 5156.648071] usbserial: USB Serial Driver core
[ 5159.798706] option: Unknown parameter `vendor'
 7238.276824] USB Serial support registered for GSM modem (1-port)
[ 7238.285369] usbcore: registered new interface driver option
[ 7238.285400] option: v0.7.2:USB Driver for GSM modems



I am kind of stuck at this point. Any help would be appreciated :)

Thanks a lot

rifat

Josh
Site Admin
Posts: 6593
Joined: 03 Nov 2007, 00:30

Re: missin ttyUSB* after usb_switchmode

Post by Josh » 14 Jan 2013, 19:59

rifo wrote:At this point, I guess that option.ko cannot know that 0x1c05 is its target. Below is the reason that I believe new_id is not available on my kernel

Code: Select all

# cat /sys/bus/usb-serial/drivers/option1/new_id               
cat: can't open '/sys/bus/usb-serial/drivers/option1/new_id': Permission denied
Did you try to change the permissions of the attribute? Do you have sufficient superuser rights?
rifo wrote:I also had some problems making use of the "new_id" mechansim in /sys/bus/... so I tried passing parameters to option.ko to no avail

Code: Select all

insmod ./usbserial.ko 
# insmod ./option.ko vendor=0x12d1 product=0x1c05
insmod: can't insert './option.ko': unknown symbol in module, or unknown parameter
This will never work. These parameters are not implemented.

rifo
Posts: 6
Joined: 11 Jan 2013, 17:06

Re: missin ttyUSB* after usb_switchmode

Post by rifo » 15 Jan 2013, 15:01

Hello again,

I have tried running the modem on a PC with success and noticed that the usb_switchmode system assigned a product id of 14c9 . I have then did the same thing on the embedded device to no avail. While searching for the
problem, it turned out that aside from the product id, one needs to change the message content too. With the below config, things work fine after loading the usbserial driver with

Code: Select all

./insmod ./usbserial.ko  vendor=0x12d1 product=0x14c9

Code: Select all

# cat usb_modeswitch.conf 
#####################################
# Huawei, newer modems
DisableSwitching=0
EnableLoggin=1
#HuaweiMode=1
#DetachStorageOnly=1
DefaultVendor=0x12d1
DefaultProduct=0x14d1

TargetVendor=0x12d1
TargetProduct=0x14c9
#TargetProductList="1001,1406,140b,140c,1412,141b,1433,14ac,1506,1436,14ac"
CheckSuccess=20

#MessageContent="55534243123456780000000000000011060000000000000000000000000000"
MessageContent="55534243123456780000000000000011062000000100000000000000000000"

I'll try to make use of the udev system right now but I don't have support for modprobe and new_id mechanisms in my system. Hopefully I'll come with a workaround.

thanks for your help

rifat

LOM
Posts: 1404
Joined: 11 Jul 2012, 15:14
Location: Koh Samui, TH

Re: missin ttyUSB* after usb_switchmode

Post by LOM » 15 Jan 2013, 17:15

You should have consulted the usb_modeswitch datapackage, you have just reinvented the wheel..

The file 12d1_14d1 contains:

# Vodafone / Huawei K3770

TargetVendor= 0x12d1
TargetProduct= 0x14c9

MessageContent="55534243123456780000000000000011062000000100000000000000000000"

Josh
Site Admin
Posts: 6593
Joined: 03 Nov 2007, 00:30

Re: missin ttyUSB* after usb_switchmode

Post by Josh » 15 Jan 2013, 20:21

rifo wrote:I'll try to make use of the udev system right now but I don't have support for modprobe and new_id mechanisms in my system.
You can work with "insmod" of course. It just needs the full path to the module file as opposed to "modprobe".

The "new_id" attribute should be an integrated feature of the "option" driver since kernel 2.6.27. Did you load the module successfully? Just don't load it with any parameters.

rifo
Posts: 6
Joined: 11 Jan 2013, 17:06

Re: missin ttyUSB* after usb_switchmode

Post by rifo » 21 Jan 2013, 11:16

Hello again,

I have modifed the udev scripts so that insmod is used and setup the rest of the udev environment. I have plugged my Vodafone / Huawei K3770 (12d1, 14d1) and it was successfully binded to the device node /dev/gsmmodem. Later on I called a pppd script and connected to the internet. Thanks for sharing such great software :)

I have then tried another modem from ZTE (19d2, 2000) but this time the dispatcher software was not able to call the usb_modeswitch binary. Below is the output I got from /var/log/messages

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Jan  1 00:01:21 modeo user.info kernel: [   96.049682] usb 1-1: New USB device found, idVendor=19d2, idProduct=2000
Jan  1 00:01:21 modeo user.info kernel: [   96.049682] usb 1-1: New USB device strings: Mfr=3, Product=2, SerialNumber=4
Jan  1 00:01:21 modeo user.info kernel: [   96.049713] usb 1-1: Product: ZTE WCDMA Technologies MSM
Jan  1 00:01:21 modeo user.info kernel: [   96.049713] usb 1-1: Manufacturer: ZTE,Incorporated
Jan  1 00:01:21 modeo user.info kernel: [   96.049743] usb 1-1: SerialNumber: MF1900AVED010000
Jan  1 00:01:21 modeo user.warn kernel: [   96.052581] usb 1-1: new config #1 exceeds power limit by 400mA
Jan  1 00:01:22 modeo user.info kernel: [   96.061706] scsi0 : usb-storage 1-1:1.0
Jan  1 00:01:22 modeo user.warn kernel: [   96.065429] usb 1-1: 500mA is over 100mA budget for port 1!
Jan  1 00:01:22 modeo user.warn kernel: [   96.065460] hub 1-0:1.0: 400mA over power budget!
Jan  1 00:01:23 modeo user.err usb_modeswitch_dispatcher: *** glibc detected *** usb_modeswitch_dispatcher: double free or corruption (!prev): 0x000c1088 ***

I have searched for the error message and saw that there was a patch issued for it (which I guess is alreay included in my version)

Code: Select all

* usb_modeswitch: handle USB devices with multiple modes
 * Version 1.2.5 (C) Josua Dietze 2012
 * Based on libusb0 (0.1.12 and above)

I would be happy if you can guide me about this problem.

Thank you very much again for your time

rifat

rifo
Posts: 6
Joined: 11 Jan 2013, 17:06

Re: missin ttyUSB* after usb_switchmode

Post by rifo » 23 Jan 2013, 12:52

Hello again,

Just wanted to inform you guys that, I have modified the script (added a couple of echo messages) to understand where the process was stuck. It turns out that the below command

Code: Select all

usb_modeswitch_dispatcher --switch-mode 1-1/1-1 /lib/udev/usb_modeswitch
sometimes isn't able to switch the dongle to 3G modem mode when it is run via the udev mechanism.

After getting stuck, if I issue the above command manually then everything works fine and the rest of the process is handled again via the udev mechanism.

Note that 1 out of 10 tries, the udev mechanism works without problems after the dongle is plugged but usually it is stuck at the switching process.

Thanks a lot for your help

Rifat

rifo
Posts: 6
Joined: 11 Jan 2013, 17:06

Re: missin ttyUSB* after usb_switchmode

Post by rifo » 23 Jan 2013, 13:01

Also, in case it may be helpful, I have run the usd_switchmode_dispatcher with Valgrind and got the below output

Code: Select all

 cat valgrind_log.txt 
==2605== Memcheck, a memory error detector
==2605== Copyright (C) 2002-2010, and GNU GPL'd, by Julian Seward et al.
==2605== Using Valgrind-3.6.0 and LibVEX; rerun with -h for copyright info
==2605== Command: usb_modeswitch_dispatcher --switch-mode 1-1/1-1 /lib/udev/usb_modeswitch
==2605== Parent PID: 1343
==2605== 
==2605== Invalid read of size 4
==2605==    at 0x190E8: Jim_EvalObj (in /usr/sbin/usb_modeswitch_dispatcher)
==2605==  Address 0x49febf4 is 4 bytes inside a block of size 56 free'd
==2605==    at 0x4831CE0: free (vg_replace_malloc.c:366)
==2605==    by 0xCAFF: Jim_DeleteHashEntry (in /usr/sbin/usb_modeswitch_dispatcher)
==2605== 
==2605== 
==2605== HEAP SUMMARY:
==2605==     in use at exit: 0 bytes in 0 blocks
==2605==   total heap usage: 12,727 allocs, 12,727 frees, 683,985 bytes allocated
==2605== 
==2605== All heap blocks were freed -- no leaks are possible
==2605== 
==2605== For counts of detected and suppressed errors, rerun with: -v
==2605== ERROR SUMMARY: 9 errors from 1 contexts (suppressed: 13 from 6)


Josh
Site Admin
Posts: 6593
Joined: 03 Nov 2007, 00:30

Re: missin ttyUSB* after usb_switchmode

Post by Josh » 24 Jan 2013, 21:21

Did you notice this error in your log?

Jan 1 00:01:21 modeo user.warn kernel: [ 96.052581] usb 1-1: new config #1 exceeds power limit by 400mA
Jan 1 00:01:22 modeo user.warn kernel: [ 96.065429] usb 1-1: 500mA is over 100mA budget for port 1!
Jan 1 00:01:22 modeo user.warn kernel:[ 96.065460] hub 1-0:1.0: 400mA over power budget!


3G modems need the full 500 mA specified as the maximum power that a standard USB port has to provide. You might need to power your hub.

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