On Tue, 2012-04-24 at 13:14 -0400, Brian J. Murrell wrote:
> Hi,
>
> I have two DVB devices in my machine that I want to be able to identify
> persistently[1]. They are typically on /dev/dvb/adapter{0,1}/frontend0
> but their order is arbitrary and can change from one boot to another.
>
> So using udevadm info I tried to find attributes for them that I could
> rely on consistently. Here is the output from:
>
> # udevadm info --attribute-walk --name /dev/dvb/adapter?/frontend0
>
> First device:
>
> looking at device '/devices/pci0000:00/0000:00:1e.0/0000:02:09.0/dvb/dvb0.frontend0':
> KERNEL=="dvb0.frontend0"
> SUBSYSTEM=="dvb"
> DRIVER==""
>
> looking at parent device '/devices/pci0000:00/0000:00:1e.0/0000:02:09.0':
> KERNELS=="0000:02:09.0"
> SUBSYSTEMS=="pci"
> DRIVERS=="cx18"
> ATTRS{vendor}=="0x14f1"
> ATTRS{device}=="0x5b7a"
> ATTRS{subsystem_vendor}=="0x0070"
> ATTRS{subsystem_device}=="0x7400"
> ATTRS{class}=="0x040000"
> ATTRS{irq}=="21"
> ATTRS{local_cpus}=="ff"
> ATTRS{local_cpulist}=="0-7"
> ATTRS{dma_mask_bits}=="32"
> ATTRS{consistent_dma_mask_bits}=="32"
> ATTRS{enable}=="1"
> ATTRS{broken_parity_status}=="0"
> ATTRS{msi_bus}==""
>
> looking at parent device '/devices/pci0000:00/0000:00:1e.0':
> KERNELS=="0000:00:1e.0"
> SUBSYSTEMS=="pci"
> DRIVERS==""
> ATTRS{vendor}=="0x8086"
> ATTRS{device}=="0x244e"
> ATTRS{subsystem_vendor}=="0x0000"
> ATTRS{subsystem_device}=="0x0000"
> ATTRS{class}=="0x060400"
> ATTRS{irq}=="0"
> ATTRS{local_cpus}=="ff"
> ATTRS{local_cpulist}=="0-7"
> ATTRS{dma_mask_bits}=="32"
> ATTRS{consistent_dma_mask_bits}=="32"
> ATTRS{enable}=="1"
> ATTRS{broken_parity_status}=="0"
> ATTRS{msi_bus}=="1"
>
> looking at parent device '/devices/pci0000:00':
> KERNELS=="pci0000:00"
> SUBSYSTEMS==""
> DRIVERS==""
>
> And the second device:
>
> looking at device '/devices/pci0000:00/0000:00:1d.7/usb1/1-3/dvb/dvb1.frontend0':
> KERNEL=="dvb1.frontend0"
> SUBSYSTEM=="dvb"
> DRIVER==""
>
> looking at parent device '/devices/pci0000:00/0000:00:1d.7/usb1/1-3':
> KERNELS=="1-3"
> SUBSYSTEMS=="usb"
> DRIVERS=="usb"
> ATTRS{configuration}==""
> ATTRS{bNumInterfaces}==" 4"
> ATTRS{bConfigurationValue}=="1"
> ATTRS{bmAttributes}=="80"
> ATTRS{bMaxPower}=="500mA"
> ATTRS{urbnum}=="5941719"
> ATTRS{idVendor}=="2040"
> ATTRS{idProduct}=="7200"
> ATTRS{bcdDevice}=="0005"
> ATTRS{bDeviceClass}=="00"
> ATTRS{bDeviceSubClass}=="00"
> ATTRS{bDeviceProtocol}=="00"
> ATTRS{bNumConfigurations}=="1"
> ATTRS{bMaxPacketSize0}=="64"
> ATTRS{speed}=="480"
> ATTRS{busnum}=="1"
> ATTRS{devnum}=="2"
> ATTRS{devpath}=="3"
> ATTRS{version}==" 2.00"
> ATTRS{maxchild}=="0"
> ATTRS{quirks}=="0x0"
> ATTRS{avoid_reset_quirk}=="0"
> ATTRS{authorized}=="1"
> ATTRS{manufacturer}=="Hauppauge"
> ATTRS{product}=="WinTV HVR-950"
> ATTRS{serial}=="*********"
>
> looking at parent device '/devices/pci0000:00/0000:00:1d.7/usb1':
> KERNELS=="usb1"
> SUBSYSTEMS=="usb"
> DRIVERS=="usb"
> ATTRS{configuration}==""
> ATTRS{bNumInterfaces}==" 1"
> ATTRS{bConfigurationValue}=="1"
> ATTRS{bmAttributes}=="e0"
> ATTRS{bMaxPower}==" 0mA"
> ATTRS{urbnum}=="52"
> ATTRS{idVendor}=="1d6b"
> ATTRS{idProduct}=="0002"
> ATTRS{bcdDevice}=="0302"
> ATTRS{bDeviceClass}=="09"
> ATTRS{bDeviceSubClass}=="00"
> ATTRS{bDeviceProtocol}=="00"
> ATTRS{bNumConfigurations}=="1"
> ATTRS{bMaxPacketSize0}=="64"
> ATTRS{speed}=="480"
> ATTRS{busnum}=="1"
> ATTRS{devnum}=="1"
> ATTRS{devpath}=="0"
> ATTRS{version}==" 2.00"
> ATTRS{maxchild}=="8"
> ATTRS{quirks}=="0x0"
> ATTRS{avoid_reset_quirk}=="0"
> ATTRS{authorized}=="1"
> ATTRS{manufacturer}=="Linux 3.2.0-18-generic ehci_hcd"
> ATTRS{product}=="EHCI Host Controller"
> ATTRS{serial}=="0000:00:1d.7"
> ATTRS{authorized_default}=="1"
>
> looking at parent device '/devices/pci0000:00/0000:00:1d.7':
> KERNELS=="0000:00:1d.7"
> SUBSYSTEMS=="pci"
> DRIVERS=="ehci_hcd"
> ATTRS{vendor}=="0x8086"
> ATTRS{device}=="0x24dd"
> ATTRS{subsystem_vendor}=="0x1043"
> ATTRS{subsystem_device}=="0x80a6"
> ATTRS{class}=="0x0c0320"
> ATTRS{irq}=="23"
> ATTRS{local_cpus}=="ff"
> ATTRS{local_cpulist}=="0-7"
> ATTRS{dma_mask_bits}=="32"
> ATTRS{consistent_dma_mask_bits}=="32"
> ATTRS{enable}=="1"
> ATTRS{broken_parity_status}=="0"
> ATTRS{msi_bus}==""
> ATTRS{companion}==""
> ATTRS{uframe_periodic_max}=="100"
>
> looking at parent device '/devices/pci0000:00':
> KERNELS=="pci0000:00"
> SUBSYSTEMS==""
> DRIVERS==""
>
> So I tried rules like:
>
> SUBSYSTEM=="dvb", ATTRS{product}=="WinTV HVR-950", SYMLINK="dvb_pvr950q"
> SUBSYSTEM=="dvb", DRIVERS=="cx18", SYMLINK="dvb_hvr1600"
>
> but those ended up symlinking to the "net0" device:
>
> lrwxrwxrwx 1 root root 17 Apr 24 12:56 /dev/dvb_hvr1600 -> dvb/adapter0/net0
> lrwxrwxrwx 1 root root 17 Apr 24 12:56 /dev/dvb_pvr950q -> dvb/adapter1/net0
>
> How can I create symlinks to the "frontend0" device rather than the
> net0 device?
Maybe by using matches on DEVPATH and/or DEVNAME along with the other
attributes you already check?
# `pactl list | grep -B3 'card_name = "CX18' | awk /Owner Module/ '{print "pactl unload-module " $3}'`
# modprobe -r cx18-alsa
# modprobe -r cx18
# udevadm monitor --kernel --udev --property --subsystem-match=dvb > foo.log &
# modprobe cx18
# fg
^C
# less foo.log
monitor will print the received events for:
UDEV - the event which udev sends out after rule processing
KERNEL - the kernel uevent
KERNEL[1335308536.171634] add /devices/pci0000:00/0000:00:14.4/0000:03:00.0/dvb/dvb0.demux0 (dvb)
UDEV_LOG=3
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:14.4/0000:03:00.0/dvb/dvb0.demux0
SUBSYSTEM=dvb
DEVNAME=dvb/adapter0/demux0
DVB_ADAPTER_NUM=0
DVB_DEVICE_TYPE=demux
DVB_DEVICE_NUM=0
SEQNUM=2218
MAJOR=212
MINOR=0
KERNEL[1335308536.177080] add /devices/pci0000:00/0000:00:14.4/0000:03:00.0/dvb/dvb0.dvr0 (dvb)
UDEV_LOG=3
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:14.4/0000:03:00.0/dvb/dvb0.dvr0
SUBSYSTEM=dvb
DEVNAME=dvb/adapter0/dvr0
DVB_ADAPTER_NUM=0
DVB_DEVICE_TYPE=dvr
DVB_DEVICE_NUM=0
SEQNUM=2219
MAJOR=212
MINOR=1
UDEV [1335308536.198925] add /devices/pci0000:00/0000:00:14.4/0000:03:00.0/dvb/dvb0.dvr0 (dvb)
UDEV_LOG=3
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:14.4/0000:03:00.0/dvb/dvb0.dvr0
SUBSYSTEM=dvb
DEVNAME=/dev/dvb/adapter0/dvr0
DVB_ADAPTER_NUM=0
DVB_DEVICE_TYPE=dvr
DVB_DEVICE_NUM=0
SEQNUM=2219
nodmraid=1
MAJOR=212
MINOR=1
TAGS=:udev-acl:
UDEV [1335308536.201584] add /devices/pci0000:00/0000:00:14.4/0000:03:00.0/dvb/dvb0.demux0 (dvb)
UDEV_LOG=3
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:14.4/0000:03:00.0/dvb/dvb0.demux0
SUBSYSTEM=dvb
DEVNAME=/dev/dvb/adapter0/demux0
DVB_ADAPTER_NUM=0
DVB_DEVICE_TYPE=demux
DVB_DEVICE_NUM=0
SEQNUM=2218
nodmraid=1
MAJOR=212
MINOR=0
TAGS=:udev-acl:
KERNEL[1335308536.258048] add /devices/pci0000:00/0000:00:14.4/0000:03:00.0/dvb/dvb0.frontend0 (dvb)
UDEV_LOG=3
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:14.4/0000:03:00.0/dvb/dvb0.frontend0
SUBSYSTEM=dvb
DEVNAME=dvb/adapter0/frontend0
DVB_ADAPTER_NUM=0
DVB_DEVICE_TYPE=frontend
DVB_DEVICE_NUM=0
SEQNUM=2222
MAJOR=212
MINOR=2
KERNEL[1335308536.260246] add /devices/pci0000:00/0000:00:14.4/0000:03:00.0/dvb/dvb0.net0 (dvb)
UDEV_LOG=3
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:14.4/0000:03:00.0/dvb/dvb0.net0
SUBSYSTEM=dvb
DEVNAME=dvb/adapter0/net0
DVB_ADAPTER_NUM=0
DVB_DEVICE_TYPE=net
DVB_DEVICE_NUM=0
SEQNUM=2223
MAJOR=212
MINOR=3
UDEV [1335308536.278415] add /devices/pci0000:00/0000:00:14.4/0000:03:00.0/dvb/dvb0.net0 (dvb)
UDEV_LOG=3
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:14.4/0000:03:00.0/dvb/dvb0.net0
SUBSYSTEM=dvb
DEVNAME=/dev/dvb/adapter0/net0
DVB_ADAPTER_NUM=0
DVB_DEVICE_TYPE=net
DVB_DEVICE_NUM=0
SEQNUM=2223
nodmraid=1
MAJOR=212
MINOR=3
UDEV [1335308536.292451] add /devices/pci0000:00/0000:00:14.4/0000:03:00.0/dvb/dvb0.frontend0 (dvb)
UDEV_LOG=3
ACTION=add
DEVPATH=/devices/pci0000:00/0000:00:14.4/0000:03:00.0/dvb/dvb0.frontend0
SUBSYSTEM=dvb
DEVNAME=/dev/dvb/adapter0/frontend0
DVB_ADAPTER_NUM=0
DVB_DEVICE_TYPE=frontend
DVB_DEVICE_NUM=0
SEQNUM=2222
nodmraid=1
MAJOR=212
MINOR=2
TAGS=:udev-acl:
Regards,
Andy W.
> Cheers,
> b.
>
> [1] You might wonder why I would care given that they both do
> quite the same thing and who cares which one is "0" and which
> one is "1". But the reality is that while they might function
> the same the HVR-1600 produces streams with "glitches" in them
> (see my other message to this list "HVR-1600 QAM recordings with
> slight glitches in them" -- but yes, otherwise I couldn't really
> care less about which was which) and the PVR-950Q produces _perfect_
> streams, so I really only want to use the HVR-1600 in "overflow"
> situations.
>
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