Tengo dos cámaras web usb en la máquina, pero en el arranque a veces cambian de /dev/videonúmero. La solución a este problema parece estar creando una nueva udevregla. He agregado esta regla en/etc/udev/rules.d/jj-video.rules:
Fix webcam 1
KERNEL=="video1", SUBSYSTEM=="video4linux", SUBSYSTEMS=="usb", ATTRS{idVendor}=="1d6b", ATTRS{idProduct}=="0001", SYMLINK+="webcam1"
Fix webcam 2
KERNEL=="video2", SUBSYSTEM=="video4linux", ATTR{name}=="Logitech QuickCam Pro 3000", KERNELS=="0000:00:1d.0", SUBSYSTEMS=="pci", DRIVERS=="uhci_hcd", ATTRS{vendor}=="0x8086", ATTRS##{device}=="0x2658", SYMLINK+="webcam2"
pero los webcamenlaces simbólicos no se crean. He intentado muchas combinaciones diferentes en este archivo. Los presentes son solo mis últimos intentos.
Encontré los parámetros en:
jjk@eee-old:~$ udevadm info -a -p $(udevadm info -q path -p /class/video4linux/video1)
La información de Udevadm comienza con el dispositivo especificado por devpath y luego sube por la cadena de dispositivos principales. Imprime para cada dispositivo encontrado, todos los atributos posibles en el formato de clave de reglas udev. Una regla que debe coincidir puede estar compuesta por los atributos del dispositivo y los atributos de un solo dispositivo principal.
looking at device '/devices/pci0000:00/0000:00:1d.0/usb2/2-2/2-2:1.0/video4linux/video1':
KERNEL=="video1"
SUBSYSTEM=="video4linux"
DRIVER==""
ATTR{name}=="Logitech QuickCam Pro 3000"
ATTR{index}=="0"
ATTR{button}=="0"
looking at parent device '/devices/pci0000:00/0000:00:1d.0/usb2/2-2/2-2:1.0':
KERNELS=="2-2:1.0"
SUBSYSTEMS=="usb"
DRIVERS=="Philips webcam"
ATTRS{bInterfaceNumber}=="00"
ATTRS{bAlternateSetting}==" 9"
ATTRS{bNumEndpoints}=="02"
ATTRS{bInterfaceClass}=="0a"
ATTRS{bInterfaceSubClass}=="ff"
ATTRS{bInterfaceProtocol}=="00"
ATTRS{supports_autosuspend}=="0"
looking at parent device '/devices/pci0000:00/0000:00:1d.0/usb2/2-2':
KERNELS=="2-2"
SUBSYSTEMS=="usb"
DRIVERS=="usb"
ATTRS{configuration}==""
ATTRS{bNumInterfaces}==" 3"
ATTRS{bConfigurationValue}=="1"
ATTRS{bmAttributes}=="a0"
ATTRS{bMaxPower}=="500mA"
ATTRS{urbnum}=="371076"
ATTRS{idVendor}=="046d"
ATTRS{idProduct}=="08b0"
ATTRS{bcdDevice}=="0002"
ATTRS{bDeviceClass}=="00"
ATTRS{bDeviceSubClass}=="00"
ATTRS{bDeviceProtocol}=="00"
ATTRS{bNumConfigurations}=="1"
ATTRS{bMaxPacketSize0}=="8"
ATTRS{speed}=="12"
ATTRS{busnum}=="2"
ATTRS{devnum}=="2"
ATTRS{devpath}=="2"
ATTRS{version}==" 1.10"
ATTRS{maxchild}=="0"
ATTRS{quirks}=="0x0"
ATTRS{avoid_reset_quirk}=="0"
ATTRS{authorized}=="1"
ATTRS{serial}=="01402100A5000000"
looking at parent device '/devices/pci0000:00/0000:00:1d.0/usb2':
KERNELS=="usb2"
SUBSYSTEMS=="usb"
DRIVERS=="usb"
ATTRS{configuration}==""
ATTRS{bNumInterfaces}==" 1"
ATTRS{bConfigurationValue}=="1"
ATTRS{bmAttributes}=="e0"
ATTRS{bMaxPower}==" 0mA"
ATTRS{urbnum}=="34"
ATTRS{idVendor}=="1d6b"
ATTRS{idProduct}=="0001"
ATTRS{bcdDevice}=="0302"
ATTRS{bDeviceClass}=="09"
ATTRS{bDeviceSubClass}=="00"
ATTRS{bDeviceProtocol}=="00"
ATTRS{bNumConfigurations}=="1"
ATTRS{bMaxPacketSize0}=="64"
ATTRS{speed}=="12"
ATTRS{busnum}=="2"
ATTRS{devnum}=="1"
ATTRS{devpath}=="0"
ATTRS{version}==" 1.10"
ATTRS{maxchild}=="2"
ATTRS{quirks}=="0x0"
ATTRS{avoid_reset_quirk}=="0"
ATTRS{authorized}=="1"
ATTRS{manufacturer}=="Linux 3.2.0-29-generic uhci_hcd"
ATTRS{product}=="UHCI Host Controller"
ATTRS{serial}=="0000:00:1d.0"
ATTRS{authorized_default}=="1"
looking at parent device '/devices/pci0000:00/0000:00:1d.0':
KERNELS=="0000:00:1d.0"
SUBSYSTEMS=="pci"
DRIVERS=="uhci_hcd"
ATTRS{vendor}=="0x8086"
ATTRS{device}=="0x2658"
ATTRS{subsystem_vendor}=="0x1043"
ATTRS{subsystem_device}=="0x82d8"
ATTRS{class}=="0x0c0300"
ATTRS{irq}=="23"
ATTRS{local_cpus}=="ff"
ATTRS{local_cpulist}=="0-7"
ATTRS{dma_mask_bits}=="32"
ATTRS{consistent_dma_mask_bits}=="32"
ATTRS{broken_parity_status}=="0"
ATTRS{msi_bus}==""
looking at parent device '/devices/pci0000:00':
KERNELS=="pci0000:00"
SUBSYSTEMS==""
DRIVERS==""
jjk@eee-old:~$
Y probó la configuración:
sudo udevadm --debug test /sys/class/video4linux/video1
main: runtime dir '/run/udev'
run_command: calling: test
adm_test: version 175
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.
parse_file: reading '/lib/udev/rules.d/40-crda.rules' as rules file
parse_file: reading '/lib/udev/rules.d/40-fuse.rules' as rules file
parse_file: reading '/lib/udev/rules.d/40-gnupg.rules' as rules file
parse_file: reading '/lib/udev/rules.d/40-hplip.rules' as rules file
parse_file: reading '/lib/udev/rules.d/40-ia64.rules' as rules file
parse_file: reading '/lib/udev/rules.d/40-inputattach.rules' as rules file
parse_file: reading '/lib/udev/rules.d/40-libgphoto2-2.rules' as rules file
parse_file: reading '/lib/udev/rules.d/40-libsane.rules' as rules file
parse_file: reading '/lib/udev/rules.d/40-ppc.rules' as rules file
parse_file: reading '/lib/udev/rules.d/40-usb_modeswitch.rules' as rules file
parse_file: reading '/lib/udev/rules.d/40-xserver-xorg-video-intel.rules' as rules file
parse_file: reading '/lib/udev/rules.d/42-qemu-usb.rules' as rules file
parse_file: reading '/lib/udev/rules.d/50-firmware.rules' as rules file
parse_file: reading '/lib/udev/rules.d/50-udev-default.rules' as rules file
parse_file: reading '/lib/udev/rules.d/55-dm.rules' as rules file
parse_file: reading '/lib/udev/rules.d/56-hpmud_support.rules' as rules file
parse_file: reading '/lib/udev/rules.d/60-cdrom_id.rules' as rules file
parse_file: reading '/lib/udev/rules.d/60-pcmcia.rules' as rules file
parse_file: reading '/lib/udev/rules.d/60-persistent-alsa.rules' as rules file
parse_file: reading '/lib/udev/rules.d/60-persistent-input.rules' as rules file
parse_file: reading '/lib/udev/rules.d/60-persistent-serial.rules' as rules file
parse_file: reading '/lib/udev/rules.d/60-persistent-storage-dm.rules' as rules file
parse_file: reading '/lib/udev/rules.d/60-persistent-storage-tape.rules' as rules file
parse_file: reading '/lib/udev/rules.d/60-persistent-storage.rules' as rules file
parse_file: reading '/lib/udev/rules.d/60-persistent-v4l.rules' as rules file
parse_file: reading '/lib/udev/rules.d/61-accelerometer.rules' as rules file
parse_file: reading '/lib/udev/rules.d/64-xorg-xkb.rules' as rules file
parse_file: reading '/lib/udev/rules.d/66-xorg-synaptics-quirks.rules' as rules file
parse_file: reading '/lib/udev/rules.d/69-cd-sensors.rules' as rules file
add_rule: IMPORT found builtin 'usb_id', replacing /lib/udev/rules.d/69-cd-sensors.rules:76
parse_file: reading '/lib/udev/rules.d/69-libmtp.rules' as rules file
parse_file: reading '/lib/udev/rules.d/69-xorg-vmmouse.rules' as rules file
parse_file: reading '/lib/udev/rules.d/69-xserver-xorg-input-wacom.rules' as rules file
parse_file: reading '/etc/udev/rules.d/70-persistent-cd.rules' as rules file
parse_file: reading '/etc/udev/rules.d/70-persistent-net.rules' as rules file
parse_file: reading '/lib/udev/rules.d/70-printers.rules' as rules file
parse_file: reading '/lib/udev/rules.d/70-udev-acl.rules' as rules file
parse_file: reading '/lib/udev/rules.d/75-cd-aliases-generator.rules' as rules file
parse_file: reading '/lib/udev/rules.d/75-net-description.rules' as rules file
parse_file: reading '/lib/udev/rules.d/75-persistent-net-generator.rules' as rules file
parse_file: reading '/lib/udev/rules.d/75-probe_mtd.rules' as rules file
parse_file: reading '/lib/udev/rules.d/75-tty-description.rules' as rules file
parse_file: reading '/lib/udev/rules.d/77-mm-ericsson-mbm.rules' as rules file
parse_file: reading '/lib/udev/rules.d/77-mm-longcheer-port-types.rules' as rules file
parse_file: reading '/lib/udev/rules.d/77-mm-nokia-port-types.rules' as rules file
parse_file: reading '/lib/udev/rules.d/77-mm-pcmcia-device-blacklist.rules' as rules file
parse_file: reading '/lib/udev/rules.d/77-mm-platform-serial-whitelist.rules' as rules file
parse_file: reading '/lib/udev/rules.d/77-mm-qdl-device-blacklist.rules' as rules file
parse_file: reading '/lib/udev/rules.d/77-mm-simtech-port-types.rules' as rules file
parse_file: reading '/lib/udev/rules.d/77-mm-usb-device-blacklist.rules' as rules file
parse_file: reading '/lib/udev/rules.d/77-mm-x22x-port-types.rules' as rules file
parse_file: reading '/lib/udev/rules.d/77-mm-zte-port-types.rules' as rules file
parse_file: reading '/lib/udev/rules.d/77-nm-olpc-mesh.rules' as rules file
parse_file: reading '/lib/udev/rules.d/78-graphics-card.rules' as rules file
parse_file: reading '/lib/udev/rules.d/78-sound-card.rules' as rules file
parse_file: reading '/lib/udev/rules.d/80-drivers.rules' as rules file
parse_file: reading '/lib/udev/rules.d/80-mm-candidate.rules' as rules file
parse_file: reading '/lib/udev/rules.d/80-udisks.rules' as rules file
parse_file: reading '/lib/udev/rules.d/85-brltty.rules' as rules file
parse_file: reading '/lib/udev/rules.d/85-hdparm.rules' as rules file
parse_file: reading '/lib/udev/rules.d/85-hplj10xx.rules' as rules file
parse_file: reading '/lib/udev/rules.d/85-keyboard-configuration.rules' as rules file
parse_file: reading '/lib/udev/rules.d/85-regulatory.rules' as rules file
parse_file: reading '/lib/udev/rules.d/85-usbmuxd.rules' as rules file
parse_file: reading '/lib/udev/rules.d/90-alsa-restore.rules' as rules file
parse_file: reading '/lib/udev/rules.d/90-alsa-ucm.rules' as rules file
parse_file: reading '/lib/udev/rules.d/90-libgpod.rules' as rules file
parse_file: reading '/lib/udev/rules.d/90-pulseaudio.rules' as rules file
parse_file: reading '/lib/udev/rules.d/95-cd-devices.rules' as rules file
parse_file: reading '/lib/udev/rules.d/95-keyboard-force-release.rules' as rules file
parse_file: reading '/lib/udev/rules.d/95-keymap.rules' as rules file
parse_file: reading '/lib/udev/rules.d/95-udev-late.rules' as rules file
parse_file: reading '/lib/udev/rules.d/95-upower-battery-recall-dell.rules' as rules file
parse_file: reading '/lib/udev/rules.d/95-upower-battery-recall-fujitsu.rules' as rules file
parse_file: reading '/lib/udev/rules.d/95-upower-battery-recall-gateway.rules' as rules file
parse_file: reading '/lib/udev/rules.d/95-upower-battery-recall-ibm.rules' as rules file
parse_file: reading '/lib/udev/rules.d/95-upower-battery-recall-lenovo.rules' as rules file
parse_file: reading '/lib/udev/rules.d/95-upower-battery-recall-toshiba.rules' as rules file
parse_file: reading '/lib/udev/rules.d/95-upower-csr.rules' as rules file
parse_file: reading '/lib/udev/rules.d/95-upower-hid.rules' as rules file
parse_file: reading '/lib/udev/rules.d/95-upower-wup.rules' as rules file
parse_file: reading '/lib/udev/rules.d/97-bluetooth-hid2hci.rules' as rules file
parse_file: reading '/etc/udev/rules.d/jj-video.rules' as rules file
udev_rules_new: rules use 259284 bytes tokens (21607 * 12 bytes), 37913 bytes buffer
udev_rules_new: temporary index used 67520 bytes (3376 * 20 bytes)
udev_device_new_from_syspath: device 0x215103e0 has devpath '/devices/pci0000:00/0000:00:1d.0/usb2/2-2/2-2:1.0/video4linux/video1'
udev_device_new_from_syspath: device 0x21510758 has devpath '/devices/pci0000:00/0000:00:1d.0/usb2/2-2/2-2:1.0/video4linux/video1'
udev_device_read_db: device 0x21510758 filled with db file data
udev_device_new_from_syspath: device 0x21510e10 has devpath '/devices/pci0000:00/0000:00:1d.0/usb2/2-2/2-2:1.0'
udev_device_new_from_syspath: device 0x21511b10 has devpath '/devices/pci0000:00/0000:00:1d.0/usb2/2-2'
udev_device_new_from_syspath: device 0x215132f8 has devpath '/devices/pci0000:00/0000:00:1d.0/usb2'
udev_device_new_from_syspath: device 0x21513650 has devpath '/devices/pci0000:00/0000:00:1d.0'
udev_device_new_from_syspath: device 0x21513980 has devpath '/devices/pci0000:00'
udev_rules_apply_to_event: GROUP 44 /lib/udev/rules.d/50-udev-default.rules:29
udev_rules_apply_to_event: IMPORT 'v4l_id /dev/video1' /lib/udev/rules.d/60-persistent-v4l.rules:7
udev_event_spawn: starting 'v4l_id /dev/video1'
spawn_read: 'v4l_id /dev/video1'(out) 'ID_V4L_VERSION=2'
spawn_read: 'v4l_id /dev/video1'(out) 'ID_V4L_PRODUCT=Logitech QuickCam Pro 3000'
spawn_read: 'v4l_id /dev/video1'(out) 'ID_V4L_CAPABILITIES=:capture:'
spawn_wait: 'v4l_id /dev/video1' [2609] exit with return code 0
udev_rules_apply_to_event: IMPORT builtin 'usb_id' /lib/udev/rules.d/60-persistent-v4l.rules:9
builtin_usb_id: /sys/devices/pci0000:00/0000:00:1d.0/usb2/2-2/2-2:1.0: if_class 10 protocol 0
udev_builtin_add_property: ID_VENDOR=046d
udev_builtin_add_property: ID_VENDOR_ENC=046d
udev_builtin_add_property: ID_VENDOR_ID=046d
udev_builtin_add_property: ID_MODEL=08b0
udev_builtin_add_property: ID_MODEL_ENC=08b0
udev_builtin_add_property: ID_MODEL_ID=08b0
udev_builtin_add_property: ID_REVISION=0002
udev_builtin_add_property: ID_SERIAL=046d_08b0_01402100A5000000
udev_builtin_add_property: ID_SERIAL_SHORT=01402100A5000000
udev_builtin_add_property: ID_TYPE=generic
udev_builtin_add_property: ID_BUS=usb
udev_builtin_add_property: ID_USB_INTERFACES=:0aff00:010100:010200:
udev_builtin_add_property: ID_USB_INTERFACE_NUM=00
udev_builtin_add_property: ID_USB_DRIVER=Philips webcam
udev_rules_apply_to_event: LINK 'v4l/by-id/usb-046d_08b0_01402100A5000000-video-index0' /lib/udev/rules.d/60-persistent-v4l.rules:10
udev_rules_apply_to_event: IMPORT builtin 'path_id' /lib/udev/rules.d/60-persistent-v4l.rules:16
udev_builtin_add_property: ID_PATH=pci-0000:00:1d.0-usb-0:2:1.0
udev_builtin_add_property: ID_PATH_TAG=pci-0000_00_1d_0-usb-0_2_1_0
udev_rules_apply_to_event: LINK 'v4l/by-path/pci-0000:00:1d.0-usb-0:2:1.0-video-index0' /lib/udev/rules.d/60-persistent-v4l.rules:17
udev_rules_apply_to_event: RUN 'udev-acl --action=$env{ACTION} --device=$env{DEVNAME}' /lib/udev/rules.d/70-udev-acl.rules:74
udev_rules_apply_to_event: LINK 'webcam1' /etc/udev/rules.d/jj-video.rules:2
udev_event_execute_rules: no node name set, will use kernel supplied name 'video1'
udev_node_add: creating device node '/dev/video1', devnum=81:1, mode=0660, uid=0, gid=44
udev_node_mknod: preserve file '/dev/video1', because it has correct dev_t
udev_node_mknod: preserve permissions /dev/video1, 020660, uid=0, gid=44
node_symlink: preserve already existing symlink '/dev/char/81:1' to '../video1'
link_find_prioritized: found 'c81:2' claiming '/run/udev/links/v4l\x2fby-id\x2fusb-046d_08b0_01402100A5000000-video-index0'
udev_device_new_from_syspath: device 0x21516748 has devpath '/devices/pci0000:00/0000:00:1d.1/usb3/3-2/3-2:1.0/video4linux/video2'
udev_device_read_db: device 0x21516748 filled with db file data
link_find_prioritized: found 'c81:1' claiming '/run/udev/links/v4l\x2fby-id\x2fusb-046d_08b0_01402100A5000000-video-index0'
link_update: creating link '/dev/v4l/by-id/usb-046d_08b0_01402100A5000000-video-index0' to '/dev/video1'
node_symlink: atomically replace '/dev/v4l/by-id/usb-046d_08b0_01402100A5000000-video-index0'
link_find_prioritized: found 'c81:1' claiming '/run/udev/links/v4l\x2fby-path\x2fpci-0000:00:1d.0-usb-0:2:1.0-video-index0'
link_update: creating link '/dev/v4l/by-path/pci-0000:00:1d.0-usb-0:2:1.0-video-index0' to '/dev/video1'
node_symlink: preserve already existing symlink '/dev/v4l/by-path/pci-0000:00:1d.0-usb-0:2:1.0-video-index0' to '../../video1'
link_find_prioritized: found 'c81:1' claiming '/run/udev/links/webcam1'
link_update: creating link '/dev/webcam1' to '/dev/video1'
node_symlink: preserve already existing symlink '/dev/webcam1' to 'video1'
udev_device_update_db: created db file '/run/udev/data/c81:1' for '/devices/pci0000:00/0000:00:1d.0/usb2/2-2/2-2:1.0/video4linux/video1'
ACTION=add
COLORD_DEVICE=1
COLORD_KIND=camera
DEVLINKS=/dev/v4l/by-id/usb-046d_08b0_01402100A5000000-video-index0 /dev/v4l/by-path/pci-0000:00:1d.0-usb-0:2:1.0-video-index0 /dev/webcam1
DEVNAME=/dev/video1
DEVPATH=/devices/pci0000:00/0000:00:1d.0/usb2/2-2/2-2:1.0/video4linux/video1
ID_BUS=usb
ID_MODEL=08b0
ID_MODEL_ENC=08b0
ID_MODEL_ID=08b0
ID_PATH=pci-0000:00:1d.0-usb-0:2:1.0
ID_PATH_TAG=pci-0000_00_1d_0-usb-0_2_1_0
ID_REVISION=0002
ID_SERIAL=046d_08b0_01402100A5000000
ID_SERIAL_SHORT=01402100A5000000
ID_TYPE=generic
ID_USB_DRIVER=Philips webcam
ID_USB_INTERFACES=:0aff00:010100:010200:
ID_USB_INTERFACE_NUM=00
ID_V4L_CAPABILITIES=:capture:
ID_V4L_PRODUCT=Logitech QuickCam Pro 3000
ID_V4L_VERSION=2
ID_VENDOR=046d
ID_VENDOR_ENC=046d
ID_VENDOR_ID=046d
MAJOR=81
MINOR=1
SUBSYSTEM=video4linux
TAGS=:udev-acl:
UDEV_LOG=6
USEC_INITIALIZED=18213768
run: 'udev-acl --action=add --device=/dev/video1'
jjk@eee-old:~$
(y correspondientemente para video2)
Me parece que mis reglas se leen, pero no se respetan. ¿Qué estoy haciendo mal?