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3 views

unitek nec upd720200 not detected

I've decided to buy an USB3.0 controller on PCI for my debian machine. I did a short research and it appeared that NEC chips will be fine. I've bought Unitek NEC UPD720200 and I does not work: I ...
2
votes
1answer
904 views

Debian USB automount

Got my USB flash automount broken after reboot. Using Debian 6, GNOME 2 My NTFS hard disk is still mounting correctly. When i connect my Android smartphone (with SD and local drive) my messages log ...
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1answer
19 views

Determine driver for network interface [duplicate]

I wanted to see which driver was associated with some of the network interfaces listed by ip link. My first thought was to find the network interfaces in /dev and look at the device major and minor ...
2
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1answer
293 views

Is it possible to simulate/force/fake an USB device unplug and replug on Linux?

So I've got a strange problem that I've been running onto. I've got a bitcoin usb miner, Bitfury, and I'm using CGMiner to mine. When I start the application, as root, the USB device is not detected ...
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1answer
23 views

USB 3G dongle internet keeps failing on Fedora 20 laptop

I use a 3G dongle for internet in my summerhouse, it has worked fine all summer, but since yesterday it has been losing connection, or something and I have to unplug it and insert it again for the ...
2
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3answers
436 views

Why doesn't xsetwacom work from udev?

I made a script to rotate my Wacom Bamboo tablet 180 degrees. It works fine when I execute it as myself (user) or root, but when started from udev (i.e. when plugging the tablet into a usb port) it ...
4
votes
1answer
609 views

can not create /dev/shm

I need to create /dev/shm on an embedded ARM system. From "Installed The Latest Changes to Current and......". I see that it can be created with mkdir /lib/udev/devices/shm, but I'm wondering what ...
1
vote
1answer
38 views

How do I send RTSP video to a program that reads from a character device?

I have an IP-CAM that streams video over RTSP and I want to detect bar codes from it with zbarcam (from Ubuntu's zbar-tools package). According zbarcam's manual, it expects to be given a video4linux ...
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3answers
17 views

Looking at the content of a character device's file [duplicate]

Why is it possible to look at the contents of a block device's file like /dev/sda using cat or a hex editor? Why can I not do the same for a character device like /dev/pts/3?
2
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1answer
298 views

udev Unable to Rename Network Device: Device or Resource Busy

I'm trying to use udev rules in order to give my network interfaces static, consistent names. However, it seems like there is some race condition happening preventing these rules from consistently ...
1
vote
1answer
573 views

Can I use a parallel port as a CUPS input device?

I have an old piece of a hardware that does diagnostics on medical equipment. It prints out results over a parallel port. Is there any way to have CUPS accept jobs from a parallel port and redirect ...
3
votes
3answers
168 views

equivalent of `grep -a /dev/sda1` on Darwin?

I want to run something like % sudo grep -i -a 'some-string' <drive device> On Linux, <drive device> would be something like /dev/sda1. How can I find the equivalent on Darwin? (In ...
3
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2answers
72 views

Transfering content of block devices

For the purpose of backups, I'd like to transfer (several) whole disk partitions over an ssh link. So the source is a block special device, and the target should be a regular file. Common tools seem ...
0
votes
1answer
894 views

How do I find out which process is using my V4L2 webcam?

I tried to run the following: $ vlc -I dummy v4l2:///dev/video0 --video-filter scene --no-audio --scene-path webcam.png --scene-prefix image_prefix --scene-format png vlc://quit --run-time=1 ...
4
votes
1answer
51 views

look up the device from its tty file?

Here is from my Ubuntu $ ls /dev/*tty* /dev/tty /dev/tty17 /dev/tty26 /dev/tty35 /dev/tty44 /dev/tty53 /dev/tty62 /dev/ttyS12 /dev/ttyS21 /dev/ttyS30 /dev/tty0 /dev/tty18 /dev/tty27 ...
2
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0answers
66 views

/dev/sda not appearing after secure erase

I decided to wipe my SSD with a secure erase before installing Arch Linux, since the Arch wiki said that it would improve performance. I followed the instructions listed on the wiki, but now when I ...
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2answers
865 views

What’s the difference between a “raw” and a “cooked” device driver?

Does this concept only apply to terminal drivers (which is what most sites cover) or to any driver in general?
2
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1answer
577 views

Map physical USB device path to the Bus/Device number returned by lsusb

I need to get the title of the attached USB device. I can do that with lsusb. udev allows some substitutions when I write rules: say, we can use $kernel to get name of the device, or $devpath to get ...
2
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1answer
18 views

PCI header in my laptop looks different from free-electrons' PCI header

I'm trying to develope a pci driver but I can not compile it because my pci header is quite different from books and references. My distribution is 3.15.7-1-ARCH. ...
2
votes
1answer
39 views

How can I set device rw permissions permanetnly on raspbian?

Im using Raspbian (distribution made for Raspberry Pi based on Debian). I have some scripts that use i2c. Normally only root has read and write permissions for i2c. Im using this command to add i2c ...
3
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3answers
416 views

Why won't Linux let me play with /dev/dsp?

I'm working through a Linux textbook, and it's telling me about devices. It says that if I send the appropriate output to /dev/dsp, then it will play a sound. The example is cat file.wav > ...
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0answers
14 views

Cross driver communication through sysfs or /dev/ [duplicate]

I have two drivers I'm developing. One needs information from the other. Is there anything wrong with one driver reading from the sys attribute / or read/write through /dev/drivername of the driver it ...
4
votes
1answer
109 views

Does Posix require any devices?

Does Posix require any devices? For example, /dev/urandom, /dev/zero or /dev/null? I suspect not because of non-*nix OSes, but wanted to ask for completeness.
3
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2answers
69 views

How to programatically detect when a device raises an interrupt?

How to programatically detect when a device raises an interrupt? This can be when a device is connected or disconnected. And also this case: for example: when a finger is held over a fingerprint ...
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4answers
1k views

Why does “cat ttyUSB0” not produce output?

I connected an infrared receiver to a USB port ... (the last line of dmesg tells device file) $ dmesg [10496.596063] usb 7-2: new full-speed USB device number 2 using uhci_hcd [10496.751112] usb 7-2: ...
4
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4answers
1k views

Special File that causes I/O error

I want to automatically test if a piece of software reacts as expected if an essential SQLite DB file fails to be read (causing an I/O error). Exactly that happened some days ago at a client. We ...
3
votes
1answer
97 views

Why does the SELinux filesystem have it's own null device?

Looking through /sys/fs/selinux, I found this: # ls -l /sys/fs/selinux/null crw-rw-rw-. 1 root root 1, 3 Jan 24 02:47 /sys/fs/selinux/null Which is identical to /dev/null: # ls -l /dev/null ...
4
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1answer
997 views

Explain EV in /proc/bus/input/devices data

Can anybody explain to me what the EV value in /proc/bus/input/devices is? The keyboard always has value 120013. Why?
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2answers
204 views

Perform an action when a wireless keyboard is connected

I need to perform a command when I connect a bluetooth keyboard. How can I 'listen' this event?
3
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1answer
1k views

How do I setup more then 10 loopback device?

From this answer the solution is to modprobe loop max_loop=64 Which makes me allowed to use 64 loopback devices then mknod -m 660 /dev/loop8 b 7 8 To create the devices. I did this for 8, 9, 10 ...
2
votes
1answer
63 views

What are the two values in < > in a device tree .dts file ?

Following is the code snippet in a device tree file: flash@0 { compatible = "n25q128"; reg = <0x0>; spi-max-frequency = <50000000>; ...
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0answers
16 views

Hotplug Device Driver Priority

Is it possible to have more than one driver for one purpose (eg. USB) included in the Linux kernel? If so, then how does the kernel decide which one to load?
2
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0answers
81 views

How to get device filename from lsusb output or by device path

Related question: USB connect/disconnect notification When the device is plugged/unplugged, I get instant notification, that's great. But to make it (almost) perfect, I also want to get device ...
1
vote
1answer
241 views

Prevent USB storage from using different device on reset

I have a hard drive in a USB enclosure that I am doing some data recovery on. The drive is in extremely bad shape and frequently resets on reads. The device registers as /dev/sdb. Sometimes, probably ...
2
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3answers
92 views

How to know if /dev/hda2 is Primary partition or Extended partition

If all four primary partitions exist on an IDE drive, they are numbered as follows: /dev/hda1 /dev/hda2 /dev/hda3 /dev/hda4 We have also the partitions on a disk with one primary partition and ...
1
vote
1answer
27 views

console (driver) not opening using any of the editor

In my initramfs, I have; [root@xilinx Peta_Microzed_15_05]# ls initramfs/dev/ console [root@xilinx Peta_Microzed_15_05]# nano initramfs/dev/console [root@xilinx Peta_Microzed_15_05]# The above ...
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4answers
3k views

Shell command to read device registers?

On a single-board computer running Linux, is there a way to read the contents of the device configuration registers that control hardware? I think it would be a wrapper for inw(), more or less. I'm ...
1
vote
1answer
148 views

Why isn't sda1 showing up in dev and how can I fix that?

I have an embedded Linux device and I was trying to copy some files to it. I plugged in a USB stick, the dmesg shows that it was recognized, but for some reason /dev/sda1 never showed up. I'm trying ...
9
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4answers
4k views

If I connect a physical device, how can I ever know which device file belongs to it?

Say I plug in several USB drives which don't get automatically mounted. How can I find out which device file belongs to which physical device, so I can mount it for example? I'm running Mac OS X but ...
2
votes
1answer
74 views

Can renaming a network device cause race conditions?

Arch uses predictable network interface names. MATLAB licenses are linked to the MAC address of eth0, so I need to rename one of my devices eth0. In a machines with only one NIC I can just turn off ...
0
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0answers
35 views

Best Practices for Configuring/Reading Sensor Devices

I have a gadget with a number of environmental sensors attached via an I2C bus, and would like to be able configure and read these sensors via an unprivileged application. Unfortunately, there ...
3
votes
2answers
274 views

PCI configuration registers problem

I'm trying to get my new Realtek RTL-8169 NIC (over CardBus) to work, but I'm having this weird problem. My lspci -x output looks like this: [root@comp]# lspci -x -d *:8169 07:00.0 Non-VGA ...
0
votes
1answer
56 views

Two Linux Mint 16 systems Skyping--one can see both parties on webcam, the other can see neither

I installed Linux Mint 16 32-bit edition on my netbook and a friend's laptop. When we Skype, I can see her live image, and I can see my own live image, so everything looks and sounds right on my end. ...
3
votes
2answers
71 views

what is the difference between Device driver and kernel module

i know that driver is a software that can communicate with the hardware in order to control the device that attached to the computer.whereas kernel module is a small piece of code that can inserted ...
0
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0answers
25 views

information about txop in ath9k wlan driver

I'm trying to implement the rate control algorithm into ath9k wireless LAN driver. I need to find if the transmission of first packet in the TXOP has failed or succeeded (ack received or not). I ...
9
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2answers
650 views

How can I find available network interfaces?

This is in regard to linux, but if anyone knows of a general *nix method that would be good. I booted a system yesterday with an ethernet cable plugged in. "NetworkManager" is not installed, so once ...
3
votes
1answer
375 views

Udev rule to match multiple node USB device

I have a 3G/GPS device that creates 5 tty nodes, although it's only one physical USB connection. Basically, a multi port usb-serial adapter. I'm trying to create some udev rules to make sure those ...
2
votes
2answers
67 views

Check if a drive has been Zeroed with xxd and uniq?

I'm looking for a way to check if the entire binary contents of a USB device are purely 0s. I'm trying this command: sudo xxd /dev/sdb | uniq but it has no output and just runs forever. I've ...
8
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2answers
5k views

How does cat know the baud rate of the serial port?

I regularly use cat to view debugging information in the console from my FPGA development board over the serial connection, but I never have had to tell linux what the baud rate is. How does cat know ...
7
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1answer
100 views

How to find which serial port is in use?

The Question: I plugged in a device (i.e. GSM modem) through a serial port (a.k.a. RS-232), and I need to see with which file in /dev/ filesystem this device was tied up, to be able to communicate ...