Fata error> USB read failed

When I use this driver, it successfully reads two devices but with the occasional error.

USB interupt read: Resource temporarily unavailable
Fatal error> USB read failed

This results in the n0 and n1 device switching. I'm unsure if the issue lies with this driver or Linux. OS is Raspbian Wheezy. I've used other drivers which also result in this interrupt error.

[padelt]

My gut feeling(!) is that this is due to the USB device somehow misbehaving and being reset and reenumerated. I have seen ordinary devices like keyboards and webcams run without any problem for weeks with no problem at all. With the temper, I could not get even one straight week of service without such a glitch.

Even worse: sometimes it returns but always return 0-values. That detail may well be due to this driver (I did not and do not fully understand the interaction pattern that it implements).

My conclusion: restart daily using a corn job to cleanup stuck devices and do not use more than one per raspi.
Sorry, I know that is not good news... :-/

To shed some more light, I've used temper.py and now pcsensor.c and both have shown this type of behavior in my custom python script. When running pcsensor in terminal with the loop (-L) option, at no point does it hang up. I've run two simultaneous terminals hitting both Temper sensors and it still runs great. When I run my custom python script and use pcsensor, that's when the collision seems to happen. I'm less inclined to think there is an issue with your driver.

import time
import subprocess
import re

while(True):
    device0=subprocess.check_output(["pcsensor","-n0","-f"])
    device1=subprocess.check_output(["pcsensor","-n1","-f"])
    dev0temp=re.search('[0-9]{1,3}\.[0-9]{2}',str(device0))
    dev1temp=re.search('[0-9]{1,3}\.[0-9]{2}',str(device1))
    try:
        temp0=float(dev0temp.group())
        temp1=float(dev1temp.group())
    except:
        pass
time.sleep(5)

[JulienSchneider]

Hi,

Same problem here, but I can add some details. I hope it can help to locate the problem, even if I think the problem is inside the sensor.
I tried on my raspberry pi (Debian7.2) and on my computer (Ubuntu10.04LTS).
My temper sensor is this one : http://pcsensor.com/index.php?_a=viewProd&productId=7
/var/log/messages says it is a "RDing TEMPer1V1.4"

1. The USB read fails every X times and X is constant. You can run pcsensor every second or every 10 seconds, it will fails every X times. For me, X=16. But if I add "sleep(5)" at line 244 in pcsensor.c, it will fails more often - every 4 times for me.

2. I made some tests, and the error come in the interrupt_read function. Seems to be in the usb_interrupt_read call, but I cannot be sure about that. I only tested with some dirty "printf" :D

3. There is no problem when using the -l option in order to loop. I tried "-l1" for a long time (about 1h) and I had no error.

4. I tried some other drivers (temper.py and some other versions of pcsensor.c), I have the same problem.

Let me know if you need some other details.

One last question : you said "restart daily using a corn job to cleanup stuck devices". Can you explain that? What do you restart? The raspi?

Thank you for reading and sorry for my poor English ^^

[FogWatch]

Same here

$ temperv14 -c
USB interrupt read: Numerical result out of range
Fatal error> USB read failed

With the following device:

$ lsusb -vd 0c45:7401

Bus 001 Device 036: ID 0c45:7401 Microdia
Device Descriptor:
bLength 18
bDescriptorType 1
bcdUSB 2.00
bDeviceClass 0 (Defined at Interface level)
bDeviceSubClass 0
bDeviceProtocol 0
bMaxPacketSize0 8
idVendor 0x0c45 Microdia
idProduct 0x7401
bcdDevice 0.01
iManufacturer 1 RDing
iProduct 2 TEMPerV1.4
iSerial 0
bNumConfigurations 1
Configuration Descriptor:
bLength 9
bDescriptorType 2
wTotalLength 59
bNumInterfaces 2
bConfigurationValue 1
iConfiguration 0
bmAttributes 0xa0
(Bus Powered)
Remote Wakeup
MaxPower 100mA
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 0
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 3 Human Interface Device
bInterfaceSubClass 1 Boot Interface Subclass
bInterfaceProtocol 1 Keyboard
iInterface 0
HID Device Descriptor:
bLength 9
bDescriptorType 33
bcdHID 1.10
bCountryCode 0 Not supported
bNumDescriptors 1
bDescriptorType 34 Report
wDescriptorLength 65
Report Descriptor: (length is 65)
Item(Global): Usage Page, data= [ 0x01 ] 1
Generic Desktop Controls
Item(Local ): Usage, data= [ 0x06 ] 6
Keyboard
Item(Main ): Collection, data= [ 0x01 ] 1
Application
Item(Global): Report ID, data= [ 0x01 ] 1
Item(Global): Usage Page, data= [ 0x07 ] 7
Keyboard
Item(Local ): Usage Minimum, data= [ 0xe0 ] 224
Control Left
Item(Local ): Usage Maximum, data= [ 0xe7 ] 231
GUI Right
Item(Global): Logical Minimum, data= [ 0x00 ] 0
Item(Global): Logical Maximum, data= [ 0x01 ] 1
Item(Global): Report Size, data= [ 0x01 ] 1
Item(Global): Report Count, data= [ 0x08 ] 8
Item(Main ): Input, data= [ 0x02 ] 2
Data Variable Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Global): Report Count, data= [ 0x01 ] 1
Item(Global): Report Size, data= [ 0x08 ] 8
Item(Main ): Input, data= [ 0x01 ] 1
Constant Array Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Global): Report Count, data= [ 0x03 ] 3
Item(Global): Report Size, data= [ 0x01 ] 1
Item(Global): Usage Page, data= [ 0x08 ] 8
LEDs
Item(Local ): Usage Minimum, data= [ 0x01 ] 1
NumLock
Item(Local ): Usage Maximum, data= [ 0x03 ] 3
Scroll Lock
Item(Main ): Output, data= [ 0x02 ] 2
Data Variable Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Global): Report Count, data= [ 0x05 ] 5
Item(Global): Report Size, data= [ 0x01 ] 1
Item(Main ): Output, data= [ 0x01 ] 1
Constant Array Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Global): Report Count, data= [ 0x05 ] 5
Item(Global): Report Size, data= [ 0x08 ] 8
Item(Global): Logical Minimum, data= [ 0x00 ] 0
Item(Global): Logical Maximum, data= [ 0xff ] 255
Item(Global): Usage Page, data= [ 0x07 ] 7
Keyboard
Item(Local ): Usage Minimum, data= [ 0x00 ] 0
No Event
Item(Local ): Usage Maximum, data= [ 0xff ] 255
(null)
Item(Main ): Input, data= [ 0x00 ] 0
Data Array Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Main ): End Collection, data=none
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x81 EP 1 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0008 1x 8 bytes
bInterval 10
Interface Descriptor:
bLength 9
bDescriptorType 4
bInterfaceNumber 1
bAlternateSetting 0
bNumEndpoints 1
bInterfaceClass 3 Human Interface Device
bInterfaceSubClass 1 Boot Interface Subclass
bInterfaceProtocol 2 Mouse
iInterface 0
HID Device Descriptor:
bLength 9
bDescriptorType 33
bcdHID 1.10
bCountryCode 0 Not supported
bNumDescriptors 1
bDescriptorType 34 Report
wDescriptorLength 41
Report Descriptor: (length is 41)
Item(Global): Usage Page, data= [ 0x00 0xff ] 65280
(null)
Item(Local ): Usage, data= [ 0x01 ] 1
(null)
Item(Main ): Collection, data= [ 0x01 ] 1
Application
Item(Local ): Usage, data= [ 0x01 ] 1
(null)
Item(Global): Logical Minimum, data= [ 0x00 ] 0
Item(Global): Logical Maximum, data= [ 0xff 0x00 ] 255
Item(Global): Report Size, data= [ 0x08 ] 8
Item(Global): Report Count, data= [ 0x08 ] 8
Item(Main ): Input, data= [ 0x02 ] 2
Data Variable Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Local ): Usage, data= [ 0x01 ] 1
(null)
Item(Global): Report Count, data= [ 0x08 ] 8
Item(Main ): Output, data= [ 0x02 ] 2
Data Variable Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Global): Usage Page, data= [ 0x0c ] 12
Consumer
Item(Local ): Usage, data= [ 0x00 ] 0
Unassigned
Item(Global): Logical Minimum, data= [ 0x80 ] 128
Item(Global): Logical Maximum, data= [ 0x7f ] 127
Item(Global): Report Size, data= [ 0x08 ] 8
Item(Global): Report Count, data= [ 0x08 ] 8
Item(Main ): Feature, data= [ 0x02 ] 2
Data Variable Absolute No_Wrap Linear
Preferred_State No_Null_Position Non_Volatile Bitfield
Item(Main ): End Collection, data=none
Endpoint Descriptor:
bLength 7
bDescriptorType 5
bEndpointAddress 0x82 EP 2 IN
bmAttributes 3
Transfer Type Interrupt
Synch Type None
Usage Type Data
wMaxPacketSize 0x0008 1x 8 bytes
bInterval 10
Device Status: 0x0000
(Bus Powered)

[daudo]

confirming this as well, I see the same after exactly 16 reads when using the python script, see padelt/temper-python#6

[wojciiii]

I can read from the sensor (usb device) once and then not again until I take it out and insert it again.

wojci@build:/remote-git/pcsensor-temper/src$ ./pcsensor -c
USB interrupt read: Resource temporarily unavailable
Fatal error> USB read failed
wojci@build:/remote-git/pcsensor-temper/src$ ./pcsensor -c -v
usb_set_debug: Setting debugging level to 255 (on)
usb_os_init: Found USB VFS at /dev/bus/usb
usb_os_find_busses: Found 004
usb_os_find_busses: Found 003
usb_os_find_busses: Found 002
usb_os_find_busses: Found 001
usb_os_find_devices: couldn't get connect info
usb_os_find_devices: Found 001 on 004
skipping descriptor 0x30
skipped 1 class/vendor specific endpoint descriptors
error obtaining child information: Operation not permitted
usb_os_find_devices: Found 017 on 003
skipped 1 class/vendor specific interface descriptors
skipped 1 class/vendor specific interface descriptors
usb_os_find_devices: couldn't get connect info
usb_os_find_devices: Found 005 on 003
skipped 1 class/vendor specific interface descriptors
usb_os_find_devices: couldn't get connect info
usb_os_find_devices: Found 004 on 003
skipped 6 class/vendor specific interface descriptors
skipped 2 class/vendor specific interface descriptors
skipping descriptor 0x25
skipped 1 class/vendor specific endpoint descriptors
skipped 2 class/vendor specific interface descriptors
skipping descriptor 0x25
skipped 1 class/vendor specific endpoint descriptors
skipped 2 class/vendor specific interface descriptors
skipping descriptor 0x25
skipped 1 class/vendor specific endpoint descriptors
skipped 2 class/vendor specific interface descriptors
skipping descriptor 0x25
skipped 1 class/vendor specific endpoint descriptors
skipped 2 class/vendor specific interface descriptors
skipping descriptor 0x25
skipped 1 class/vendor specific endpoint descriptors
skipped 2 class/vendor specific interface descriptors
skipping descriptor 0x25
skipped 1 class/vendor specific endpoint descriptors
skipped 2 class/vendor specific interface descriptors
skipping descriptor 0x25
skipped 1 class/vendor specific endpoint descriptors
skipped 2 class/vendor specific interface descriptors
skipping descriptor 0x25
skipped 1 class/vendor specific endpoint descriptors
skipped 2 class/vendor specific interface descriptors
skipping descriptor 0x25
skipped 1 class/vendor specific endpoint descriptors
skipped 2 class/vendor specific interface descriptors
skipping descriptor 0x25
skipped 1 class/vendor specific endpoint descriptors
skipped 2 class/vendor specific interface descriptors
skipping descriptor 0x25
skipped 1 class/vendor specific endpoint descriptors
skipped 2 class/vendor specific interface descriptors
skipping descriptor 0x25
skipped 1 class/vendor specific endpoint descriptors
usb_os_find_devices: couldn't get connect info
usb_os_find_devices: Found 003 on 003
skipped 1 class/vendor specific interface descriptors
usb_os_find_devices: couldn't get connect info
usb_os_find_devices: Found 002 on 003
usb_os_find_devices: couldn't get connect info
usb_os_find_devices: Found 001 on 003
error obtaining child information: Inappropriate ioctl for device
error obtaining child information: Operation not permitted
error obtaining child information: Operation not permitted
error obtaining child information: Operation not permitted
error obtaining child information: Operation not permitted
error obtaining child information: Operation not permitted
usb_os_find_devices: couldn't get connect info
usb_os_find_devices: Found 002 on 002
usb_os_find_devices: couldn't get connect info
usb_os_find_devices: Found 001 on 002
error obtaining child information: Operation not permitted
error obtaining child information: Operation not permitted
usb_os_find_devices: couldn't get connect info
usb_os_find_devices: Found 002 on 001
usb_os_find_devices: couldn't get connect info
usb_os_find_devices: Found 001 on 001
error obtaining child information: Operation not permitted
error obtaining child information: Operation not permitted
lvr_winusb with Vendor Id: c45 and Product Id: 7401 found.
USB error: could not detach kernel driver from interface 0: No data available
Device already detached
USB error: could not detach kernel driver from interface 1: No data available
Device already detached
01 01 00 00 00 00 00 00
01 80 33 01 00 00 00 00
USB interrupt read: Resource temporarily unavailable
Fatal error> USB read failed

[padelt]

@wojciiii , I have no real idea why that is happening. That said, I do not think much about this C-version of pcsensor-temper as I exclusively use the python-version here: https://github.com/padelt/temper-python

I do have one idea though: A year ago, @amorphic added a reset of the USB device after each read cycle. You can see the relevant code change in temper-python here:

padelt/temper-python@a9c8b68#diff-19c78b0104bf03153b342369297c254dR157

That may still be missing in pcsensor-temper and may help with this situation.

[stefansundin]

I added a call to usb_reset(lvr_winusb) just before the call to usb_set_configuration() (here) and now I can run the program more than once. I moved the self._device.reset() call in temper-python to the same location (just before self._device.set_configuration()) and I can now run both of these programs after each other.

See my fork here: https://github.com/stefansundin/pcsensor-temper