Questions tagged [irq]

An interrupt request is a hardware signal sent to the processor that temporarily stops a running program and allows to handle a hardware event.

In an IBM PC compatible personal computer, an interrupt request (or IRQ) is a hardware signal sent to the processor that temporarily stops a running program and allows a special program, an interrupt handler, to run instead. Interrupts are used to handle such events as data receipt from a modem or network, or a key press or mouse movement. The interrupt request level (IRQL) is the priority of an interrupt request.

Related tags:

209 questions
0
votes
1 answer

how to interpret the smp_affinity output

My lscpu output is: I have only one entry in /proc/interrupts for my NIC: smp_affinity for my NIC eth0 is: Since I have only 8 CPUs, I expected the smp_affinity value to have 8 bits, each bit for one CPU core, but I have 32 bits. How do I…
user2761431
  • 925
  • 2
  • 11
  • 26
0
votes
1 answer

A bootloader that I am making doesn't get any IRQ12

The computer in which I test my operating system is a laptop with a touchpad. When I power the computer on, it reads the keyboard, but after I touch the touchpad, it doesn't read the touchpad nor the keyboard either. And I also use qemu and on qemu…
Bolgeg
  • 41
  • 5
0
votes
1 answer

STM32F103 blue pill ADC example

After searching for a veeery long time (more then 3 months) in all the main places where to get info and reading the datasheet of the chip I would like to ask the STM32 specialists inhere if there is a example for using the ADC maybe with DMA from…
Eric
  • 1
  • 1
  • 3
0
votes
1 answer

STM32L4R5xx hangs when an external interrupt is enabled

I would like to use the pin PC3 as an external interrupt. Whenever I enable the interrupt I end up in the infinite loop. This is how I init a gpio and its interrupt: __HAL_RCC_GPIOC_CLK_ENABLE(); GPIO_InitStruct.Pin = GPIO_PIN_3; …
user
  • 95
  • 1
  • 9
0
votes
0 answers

Get PIC's Intrerrupt Mask Register (IMR) and Disable a special IRQ

I'm trying to know, how IRQs map to a special Interrupt Descriptor Table (IDT) entry from PIC perspective. The link here describes how to disable all the IRQs by setting 0xff as the Interrupt Mask Register by using 0x21 and 0xA1 bus lines. As I know…
Embrace
  • 23
  • 6
0
votes
0 answers

zynq linux IRQ from PL

I am working with a zynq board , z-turn, and I added two interruptions coming from PL, I edited my device tree with : amba_pl { #address-cells = <0x1>; #size-cells = <0x1>; compatible = "simple-bus"; ranges; …
0
votes
1 answer

arm - interrupt enabling

I'm trying to enable interrupts and timer 2 on Allwinner A20 (User Manual). cpsr reads 0x60000113. GICD_CTRL reads 1. GICC_CTRL reads 1. GICD_ITARGETSR0 reads 0x01010101. And GICD_IIDR reads 0x0100143b. IRQ_ENABLE_REG of the timer was enabled.…
0
votes
0 answers

IRQ Tables and addresses

I've been spending a few hours of searching and I can't seem to find what I need. I'm looking at reading the IRQ Tables, I know this is kernel level, I have access to the memory addresses, but I can't find a place showing the structure of the…
0
votes
1 answer

Registering custom interrupt handler for Intel PT

I'm currently writing a custom driver for Intel Processor Trace (PT). According to Intel's Software Developers Manual Vol. 3C 36-13, the CPU "will attempt to signal a ToPA PMI interrupt before the output wraps and overwrites the top of the…
JacksGT
  • 131
  • 8
0
votes
0 answers

IRQ interrupt is not get triggered

My Driver Code : static irqreturn_t pwm_cnt_interrupt(int irq, void *data) { printk("==> %s\r\n", __func__); return IRQ_HANDLED; } static int ecap_cnt_probe(struct platform_device *pdev) { pc = devm_kzalloc(&pdev->dev, sizeof(*pc),…
0
votes
0 answers

How can I know on which CPU a NIC driver's interrupt service routine running?

I want to manually control a NIC's IRQ affinity in order to do some low-latency performance experiments. and I want to see on which CPU the NIC driver's interrupt service routine (ISR) resides. On Fedora 19, I can see the the information on…
cwang.sh
  • 23
  • 3
0
votes
1 answer

Getting access to the input handler from the IRQ lane

Whilst researching the input event system in the kernel, I came across the need to access the input handlers that have already been registered with an IRQ lane given only the irq lane (just the integer). Is there a method to access ALL event…
0
votes
1 answer

In linux kernel, will free_irq put system in danger?

I think the answer is NO, but sorry I'm new to kernel and I would like to know why. I checked kernel code and I found that when threaded irq is going to be freed, it will call kthread_stop(action->thread); Isn't it a little risky? In linux driver we…
Adrian Hu
  • 3
  • 1
0
votes
1 answer

kernel IRQ domain list

I'm developping a simple GPIO driver for a SoC running linux (newbie's level), I am facing problem because IRQ numbers are different from those in datasheets. I've learned that effective IRQ manager may create IRQ domains. However the unsigned int…
SOFuser
  • 134
  • 1
  • 10
0
votes
1 answer

cannot find request_irq(), irq.h or interrupt.h to use in a simple interrupt handler

I am trying to write a simple handler for interrupts from a GPIO port. I have never tried to register an IRQ before, but see discussions on using request_irq and request_threaded_irq, but I cannot find header files containing these on my CentOS7 or…
Terry L Anderson
  • 263
  • 1
  • 11