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Questions tagged [drivers]

A device driver or software driver is a computer program allowing higher-level computer programs to interact with a hardware device.

72
votes
12answers
11k views

What's the philosophy behind delaying writing data to disk?

In Linux, a finished execution of a command such as cp or dd doesn't mean that the data has been written to the device. One has to, for example, call sync, or invoke the "Safely Remove" or "Eject" ...
64
votes
3answers
87k views

What is difference between User space and Kernel space?

Is Kernel space used when Kernel is executing on the behalf of the user program i.e. System Call? Or is it the address space for all the Kernel threads (for example scheduler)? If it is the first one,...
64
votes
4answers
67k views

Moving linux install to a new computer

I know that it can, in some circumstances, be difficult to move a Windows installation from one computer to another (physically move the hard drive), but how does that work on linux? Aren't most of ...
62
votes
6answers
54k views

What is the difference between kernel drivers and kernel modules?

When I do a lspci -k on my Kubuntu with a 3.2.0-29-generic kernel I can see something like this: 01:00.0 VGA compatible controller: NVIDIA Corporation G86 [Quadro NVS 290] (rev a1) Subsystem: ...
51
votes
3answers
16k views

Does the kernel have a main() function? [closed]

I am learning device drivers and Kernel programming. According to Jonathan Corbet's book, there is no main() function in device drivers. So I two questions: Why don't we need a main() function in ...
45
votes
4answers
52k views

How to find the driver (module) associated with a device on Linux?

On Linux, given: a device, for example /dev/sda, and its major and minor numbers, for example 8, 0, how can I know which module / driver is "driving" it? Can I dig into /sys or /proc to discover ...
34
votes
4answers
55k views

Find out which modules are associated with a usb device?

Could you recommend a way to figure out which driver is being used for a USB device. Sort of a usb equivalent of lspci -k command.
34
votes
2answers
49k views

What is the difference between ioctl(), unlocked_ioctl() and compat_ioctl()?

Going through the linux 2.6.36 source code at lxr.linux.no, I could not find the ioctl() method in file_operations. Instead I found two new calls: unlocked_ioctl() and compat_ioctl(). What is the ...
30
votes
7answers
206k views

How to close X Server, to avoid errors while updating nVidia driver?

I tried to update my nVidia driver but I got an error when I ran the driver installation. See the error: ERROR: You appear to be running an X server; please exit X before ...
30
votes
1answer
41k views

How to assign USB driver to device

This question is two-fold: First, how do you manually detach a driver from a USB device and attach a different one? For example, I have a device that when connected automatically uses the usb-...
26
votes
1answer
35k views

How to use Linux kernel driver bind/unbind interface for USB-HID devices?

First background. I am developing a driver for Logitech game-panel devices. It's a keyboard with a screen on it. The driver is working nicely but by default the device is handled by HID. In order to ...
25
votes
3answers
3k views

Why are some Intel family 6 CPU models (Core 2, Pentium M) not supported by intel_idle?

I've been tuning my Linux kernel for Intel Core 2 Quad (Yorkfield) processors, and I noticed the following messages from dmesg: [ 0.019526] cpuidle: using governor menu [ 0.531691] clocksource: ...
23
votes
5answers
18k views

Is USB-to-USB data transfer between two Linux OSes possible?

I want to create a USB-to-USB data transfer system in Linux (preferably Ubuntu). For this I want to use no external hardware or switch (except this cable). It's going to be like mounting a USB drive ...
22
votes
3answers
75k views

How to find out which Wi-Fi driver is installed?

I know about lsmod, but how do I figure out which driver does what?
22
votes
2answers
13k 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?
21
votes
2answers
3k views

Is a device driver in Linux a program/process or is it just a library?

Is a device driver a program that runs on its own, or is it just a library (a group of functions) that is loaded in memory and programs can call one of its functions (so it is not running on its own). ...
21
votes
1answer
601 views

How to get started writing drivers?

I have a throw-away cheap laptop I'd like to twiddle around, a Thinkpad SL 500. What bothers me are two leds, the one for wireless connectivity, and the one for hibernation, which don't light up at ...
20
votes
5answers
30k views

How do character device or character special files work?

I am trying to understand character special files. From wikipedia, I understand that these files "provide an interface" for devices that transmit data one character at a time. My understanding is ...
19
votes
2answers
36k views

Which driver is handling my touchpad?

I would like to know how to determine which driver (out of those below) is handling my touchpad: appletouch.ko.gz, cyapa.ko.gz, sermouse.ko.gz, synaptics_usb.ko.gz, bcm5974.ko.gz, psmouse.ko.gz, ...
19
votes
2answers
14k views

Connection problem with USB3 external storage on Linux (UAS driver problem)

On Ubuntu 15.10, when I want to format using the NTFS file system an external 4TO disk connected by USB3 (on a StarTech USB/eSATA hard disk dock), I have a lot of I/O errors, and the format fails. I ...
18
votes
3answers
24k views

Attaching USB-Serial device with custom PID to ttyUSB0 on embedded

I'm attempting to get an FTDI USB-Serial device with a custom PID to automatically (or even manually) attach to ttyUSB%n, without much success. The device's normal VID/PID is 0403/6001. When ...
18
votes
2answers
1k views

How is new hardware support added to the linux kernel?

Imagine there's a company A that releases a new graphics adapter. Who manages the process that results in this new graphics adapter being supported by the Linux kernel in the future? How does that ...
18
votes
2answers
28k views

How to debug the input from an input-device (/dev/input/event*)

I have a IR receiver that is using the imon-driver and I would like to get it working with the kernel. Right now half of the keys on the remote (image) works, but an all important think like the ...
17
votes
2answers
17k views

How to setup GParted video mode in Oracle Virtualbox?

I'm trying to boot GParted live 0.14.1-6 within Oracle Virtualbox 4.2.6 r82870 (Extension Pack installed). The host OS is Windows 7, the physical graphic card is an AMD Radeon HD 6900. The physical ...
17
votes
3answers
6k views

Why don't you need to update drivers? (Or do you?)

Why one does not need to update Linux drivers? Is it due to the open source community building good drivers before they are submitted to the kernel, or do driver updates occur when I do normal system ...
16
votes
4answers
5k views

Should I restart after a pacman upgrade?

after running sudo pacman -Syyu or sudo pacman -S [something to install] should I restart just to be safe?
16
votes
2answers
6k views

Which NVIDIA driver should I use?

I have an NVIDIA GeForce 9500 GT. I'm currently using nvidia-331 since the Nouveau open drivers were giving me some trouble. But I have several other drivers to select, see: What are the ...
14
votes
4answers
14k views

Error compiling drivers for Ralink RT2870

Im trying to install drivers for a rosewill RNX-N600UBE wireless card (Ralink RT2870 chipset) on Kali Linux. I downloaded the drivers form their website and unpacked/unzipped them, but now when i try ...
14
votes
4answers
1k views

How do I implement a file system driver driver in Linux? [closed]

Assume that I have invented a new file system, and now I want to create a file system driver for it. How would I implement this file system driver, is this done using a kernel module? And how can ...
13
votes
1answer
12k views

How to (really) disable NCQ in Linux

I implemented my own Serial-ATA Host-Bus-Adapter (HBA) in VHDL and programmed it onto a FPGA. A FPGA is chip which can be programmed with any digital circuit. It's also equipped with serial ...
13
votes
3answers
13k views

Microphone - static background noise suppression on Linux

My soundcard is Realtek ALC 892. On Windows 7 I use official Realtek drivers, on Linux I use PulseAudio (on Ubuntu 13.10). On both Windows and Linux, when I enable microphone boost +30db (required ...
12
votes
1answer
1k views

Why need drivers for both x server and the linux kernel?

Can someone explain why two sets of drivers are needed, one in the Linux kernel and one in X? I understand that the device drivers are in the kernel, but what is the role of those in the xserver? ...
12
votes
2answers
3k views

Using many monitors (4+) in linux

I want to be able to run more than 4 monitors (maybe 6) and it's extremely confusing what's compatible now with the Displayport cards coming out. Right now I have an ATI card that only has 2 HDMI ...
12
votes
1answer
4k views

What's the difference between the drivers r8169 and r8168?

Realtek provides the source code for the r8168 driver which is based on the r8169 driver from the kernel tree if I may believe their source: /* * This driver is modified from r8169.c in Linux kernel ...
11
votes
3answers
57k views

How do I display the name of my audio card driver from the command line in Lubuntu 11.10?

I am running Lubuntu 11.10 and I want to display my Audio / Sound Card Driver from the command line.
11
votes
3answers
7k views

How do Linux drivers work and where do I find them? (esp. NIC driver)

I am wondering how a driver functions under Linux. Are drivers a single file that can be edited? Is there a list of current drivers in use or is there a different place to find them for each device? ...
11
votes
2answers
19k views

How to find out which X11 driver system is using?

How to find out which X11 driver system is using? For my chip openchrome is the best driver but I suspect that system is not using it. I just need at least 2D acceleration. How can I check? Here is ...
11
votes
1answer
260 views

Why kernel modesetting, instead of privilege separation?

Kernel modesetting was kind of painful to get on Linux at first, but now it's pretty awesome to have. I mean, X not need to run as root? High-res hardware accelerated consoles? Cool stuff. Problem is,...
10
votes
5answers
46k views

How to get the version of my nvidia driver?

I tried using cat /proc/driver/nvidia/version but it says the file does not exist. Is there any alternative way to do that? I tried to look manually for that file, but I couldn't find it. I also ...
10
votes
5answers
22k views

Prevent a USB external hard drive from sleeping

Does anyone know if there is an elegant way to tell an external usb drive not to spin down after a period of inactivity? I've seen cron based solutions that write a file every minute, but nothing ...
10
votes
3answers
4k views

How does libusb access kernel stuff?

From what I understand: Generally speaking, a driver runs in kernel space and can be called from user space. Only code in kernel space can call usb low level things / ioctl libusb is a library, so ...
10
votes
1answer
3k views

What driver is behind a certain device file?

Given a device file, say /dev/sdb, is it possible to determine what driver is behind it? Specifically, I want to determine what driver my storage devices are using. fdisk -l lists 2 devices: /dev/sda ...
10
votes
2answers
8k views

Capturing key input from events device and mapping it (toggle TouchPad key is unmapped)

I have a Lenovo IdeaPad Yoga 13 with Ubuntu 13.10 Installed. The device has a "Toggle TouchPad" button on the keyboard (F5). The keyboard's F* buttons are reversed (so to get F5, I need to press Fn + ...
10
votes
3answers
23k views

mptscsih: ioc0: task abort: SUCCESS (rv=2002) causes 30 seconds freezing

I/O to my software RAID6 often freezes for around 30 seconds after which everything is back to normal. After the freeze is over this is put into syslog: Mar 14 18:43:57 server kernel: [35649.816060] ...
10
votes
4answers
6k views

wireless is disabled by hardware switch even when not

I have a spartan computer. It has a built-in wireless module that up until recently I've had no issues with. The current problem is this: every time I shutdown the computer and it boots back up, I am ...
10
votes
1answer
961 views

Driver is sometimes loaded, sometimes not

I was assigned an Ubuntu desktop with some stuff already on it. I did not reformat it, but attached a mini-PCI wireless card over a PCI to mini-PCI adapter. I manually built the madwifi driver and ...
9
votes
1answer
38k views

Is there a standard directory in Linux where my driver files are stored?

I need to find my drivers for the sound card and graphic card, do you know how to find their paths and if they are stored logically in one directory?
9
votes
3answers
19k views

How can I tell if my wifi dongle has access-point capabilities?

I have a Realtek 8191SU USB wifi dongle for use on my Raspberry Pi. I'm trying to set up a wifi access point using this tutorial. However, I'm running into a few errors, and I suspect it might be ...
9
votes
2answers
10k views

what is the difference between Device driver and kernel module [duplicate]

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 ...
9
votes
2answers
18k views

How can I get xrandr to detect both nvidia cards: 2 x GTX480, triple-head?

I am running Linux Mint 16 (Petra) I am running the default driver nvidia-319 shipped with the distro I have 2x GTX480 cards I have 3 monitors Using the Nvidia driver, all monitors and GPUs are picked ...