[yocto] adding a udev entry for a camera

Khem Raj raj.khem at gmail.com
Thu Oct 31 09:20:26 PDT 2013


On Thu, Oct 31, 2013 at 8:55 AM, Gary Thomas <gary at mlbassoc.com> wrote:
> On 2013-10-31 09:45, Edward Vidal wrote:
>>
>> Hello all,
>> less /etc/udev/rules.d/10-c920.rules
>> WARNING: terminal is not fully functional
>> SUBSYSTEM=="video4linux", BUS=="usb", ATTRS{idvendor}=="0x046d",
>> ATTRS{idProduct
>> }=="0x082d", NAME="video0", MODE:="0660"
>> It appears the key BUS is not correct based on the tests below.
>> My mknod is /bin/mknod.
>> find / -name sysfs
>> /usr/include/sysfs
>> /usr/src/kernel/fs/sysfs
>
>
> Note: chasing this udev behaviour is a waste of time if the kernel doesn't
> recognize
> and support your device.

Look at the first post. Its recognised and displayed ok with lsusb.

>
> Have you even looked to see if this camera is supported in your kernel?  I
> could
> not find a driver for it when I looked, even in the latest mainline kernel.
>
> What kernel are you trying to use?
>
>>
>> udevadm test --action=add /usr/include/sysfs or udevadm test --action=add
>> /usr/src/kernel/fs/sysfs unable to open device
>> '/sys/usr/src/kernel/fs/sysfs'
>> run_command: calling: test
>> adm_test: version 182
>> This program is for debugging only, it does not run any program,
>> specified by a RUN key. It may show incorrect results, because
>> some values may be different, or not available at a simulation run.
>>
>> builtin_kmod_init: load module index
>> add_matching_files: unable to open '/var/run/udev/rules.d': No such file
>> or directory
>> parse_file: reading '/etc/udev/rules.d/10-c920.rules' as rules file
>> add_rule: unknown key 'BUS' in /etc/udev/rules.d/10-c920.rules:1
>> add_rule: invalid rule '/etc/udev/rules.d/10-c920.rules:1'
>>
>> lots of output
>>
>> udev_rules_new: rules use 18408 bytes tokens (1534 * 12 bytes), 12756
>> bytes buffer
>> udev_rules_new: temporary index used 12800 bytes (640 * 20 bytes)
>> unable to open device '/sys/usr/include/sysfs'
>> builtin_kmod_exit: unload module index
>>
>> Do I add RUN+="/bin/mknod /dev/video0 c 81 0" see below new version of
>> 1--c920.rules
>> cat 10-c920.rules
>> SUBSYSTEM=="video4linux", BUS=="usb", ATTRS{idvendor}=="0x046d",
>> ATTRS{idProduct}=="0x082d", NAME="video0", MODE:="0660", RUN+="/bin/mknod
>> /dev/video0 c 81 0"
>> udevadm test --action=add /usr/src/kernel/fs/sysfs
>> run_command: calling: test
>> adm_test: version 182
>> This program is for debugging only, it does not run any program,
>> specified by a RUN key. It may show incorrect results, because
>> some values may be different, or not available at a simulation run.
>>
>> builtin_kmod_init: load module index
>> add_matching_files: unable to open '/var/run/udev/rules.d': No such file
>> or directory
>> parse_file: reading '/etc/udev/rules.d/10-c920.rules' as rules file
>> add_rule: unknown key 'BUS' in /etc/udev/rules.d/10-c920.rules:1
>> add_rule: invalid rule '/etc/udev/rules.d/10-c920.rules:1'
>>
>> Where do you find information for working with rules other than just some
>> examples?
>>
>> Thanks
>>
>>
>> On Thu, Oct 31, 2013 at 8:41 AM, Khem Raj <raj.khem at gmail.com
>> <mailto:raj.khem at gmail.com>> wrote:
>>
>>
>>     On Wed, Oct 30, 2013 at 6:12 PM, Edward Vidal
>> <vidal.develone at gmail.com <mailto:vidal.develone at gmail.com>> wrote:
>>     > Hello,
>>     > This is when I connect the camera
>>     > udevadm monitor test
>>     > monitor will print the received events for:
>>     > UDEV - the event which udev sends out after rule processing
>>     > KERNEL - the kernel uevent
>>     >
>>     > KERNEL[803.263336] add
>>     > /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4
>> (usb)
>>     > KERNEL[803.267456] add
>>     >
>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/1-2.3.4:1.0
>>     > (usb)
>>     > KERNEL[803.269287] add
>>     >
>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/1-2.3.4:1.1
>>     > (usb)
>>     > KERNEL[803.269958] add
>>     >
>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/1-2.3.4:1.2
>>     > (usb)
>>     > KERNEL[803.270721] add
>>     >
>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/1-2.3.4:1.3
>>     > (usb)
>>     > KERNEL[803.276214] add
>>     >
>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/usb_device/usbdev1.15
>>     > (usb_device)**********
>>     > UDEV  [803.277191] add
>>     > /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4
>> (usb)
>>     > UDEV  [803.306091] add
>>     >
>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/usb_device/usbdev1.15
>>     > (usb_device)
>>     > UDEV  [803.318603] add
>>     >
>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/1-2.3.4:1.2
>>     > (usb)
>>     > UDEV  [803.324249] add
>>     >
>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/1-2.3.4:1.1
>>     > (usb)
>>     > UDEV  [803.329712] add
>>     >
>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/1-2.3.4:1.0
>>     > (usb)
>>     > UDEV  [803.333160] add
>>     >
>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/1-2.3.4:1.3
>>     > (usb)
>>     >
>>     > still no /dev/video0
>>     > ls -la /dev/v*
>>     > crw-rw---- 1 root tty 7,   0 Jan  1  2000 /dev/vcs
>>     > crw-rw---- 1 root tty 7,   1 Jan  1  2000 /dev/vcs1
>>     > crw-rw---- 1 root tty 7,   2 Jan  1  2000 /dev/vcs2
>>     > crw-rw---- 1 root tty 7,   3 Oct 29 13:51 /dev/vcs3
>>     > crw-rw---- 1 root tty 7, 128 Jan  1  2000 /dev/vcsa
>>     > crw-rw---- 1 root tty 7, 129 Jan  1  2000 /dev/vcsa1
>>     > crw-rw---- 1 root tty 7, 130 Jan  1  2000 /dev/vcsa2
>>     > crw-rw---- 1 root tty 7, 131 Oct 29 13:51 /dev/vcsa3
>>     > root at beagleboard:~# lsusb
>>     > Bus 001 Device 002: ID 0424:9514 Standard Microsystems Corp.
>>     > Bus 001 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
>>     > Bus 002 Device 001: ID 1d6b:0002 Linux Foundation 2.0 root hub
>>     > Bus 001 Device 003: ID 0424:ec00 Standard Microsystems Corp.
>>     > Bus 001 Device 004: ID 0409:0059 NEC Corp. HighSpeed Hub
>>     > Bus 001 Device 005: ID 413c:2005 Dell Computer Corp. RT7D50 Keyboard
>>     > Bus 001 Device 006: ID 046d:c001 Logitech, Inc. N48/M-BB48
>> [FirstMouse Plus]
>>     > Bus 001 Device 015: ID 046d:082d Logitech, Inc.
>>     >
>> ***********************************************************************************
>>     >
>>     >
>>     > udevadm monitor --udev
>>     > monitor will print the received events for:
>>     > UDEV - the event which udev sends out after rule processing
>>     > camera removed*****************************************************
>>     > UDEV  [1325.916811] remove
>>     >
>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/1-2.3.4:1.1
>>     > (usb)
>>     > UDEV  [1325.918489] remove
>>     >
>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/1-2.3.4:1.0
>>     > (usb)
>>     > UDEV  [1325.919282] remove
>>     >
>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/1-2.3.4:1.2
>>     > (usb)
>>     > UDEV  [1325.923005] remove
>>     >
>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/1-2.3.4:1.3
>>     > (usb)
>>     > UDEV  [1325.928437] remove
>>     >
>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/usb_device/usbdev1.15
>>     > (usb_device)
>>     > UDEV  [1325.932709] remove
>>     > /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4
>> (usb)
>>     > camera added
>>     >
>> ***************************************************************************
>>     > UDEV  [1329.344727] add
>>     > /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4
>> (usb)
>>     > UDEV  [1329.376313] add
>>     >
>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/usb_device/usbdev1.16
>>     > (usb_device)
>>     > UDEV  [1329.389008] add
>>     >
>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/1-2.3.4:1.2
>>     > (usb)
>>     > UDEV  [1329.396241] add
>>     >
>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/1-2.3.4:1.1
>>     > (usb)
>>     > UDEV  [1329.401795] add
>>     >
>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/1-2.3.4:1.0
>>     > (usb)
>>     > UDEV  [1329.406739] add
>>     >
>> /devices/platform/usbhs_omap/ehci-omap.0/usb1/1-2/1-2.3/1-2.3.4/1-2.3.4:1.3
>>     > (usb)
>>     >
>>     > This is what I get in /var/log/messages
>>     > Oct 29 14:17:28 beagleboarduser.info <http://user.info> kernel: usb
>> 1-2.3.4: USB disconnect,
>>     > device number 16
>>     > Oct 29 14:17:31 beagleboarduser.info <http://user.info> kernel: usb
>> 1-2.3.4: new high-speed
>>
>>     > USB device number 17 using ehci-omap
>>     > Is there anything else that I can test  / provide
>>
>>     OK another thing to try is
>>
>>     udevadm test --action=add /sys/....
>>
>>     where /sys/... is path to your device in sysfs
>>
>>     this should give enough reason to what udev is doing when its getting
>> an add
>>     event for this device.
>>
>>     Secondly in your udev rule refer mknod with absolute path like
>>     /sbin/mknod or /bin/mknod where ever it is
>>
>>
>>
>>
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>>
>
> --
> ------------------------------------------------------------
> Gary Thomas                 |  Consulting for the
> MLB Associates              |    Embedded world
> ------------------------------------------------------------
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