在驱动程序中使用request_threaded_irq()为什么不使用request_irq()?两者之间有什么区别? [英] request_threaded_irq() is used in the driver why not request_irq()? What are the differences between two?

问题描述

我发布了这是讨论关于request_threaded_irq的主题，但没有得到任何答复.因此，我正在重新发布它.

I posted this is the thread which discussed about request_threaded_irq but I did not get any reply. So I am posting it freshly.

我正在开发用于电容式触摸屏的触摸屏驱动程序.它使用request_threaded_irq()调用而不是request_irq().我无法理解两者之间的基本区别.它说:-

I am working on a touchscreen driver for capacitive touchscree. It used request_threaded_irq() call instead of request_irq(). I could not understand the basic difference betweeen two. It says :-

名称

request_threaded_irq —分配中断行

request_threaded_irq — allocate an interrupt line

简介

int request_threaded_irq(无符号int irq，irq_handler_t处理程序，irq_handler_t thread_fn，无符号长irqflags，const char * devname，void * dev_id)；

int request_threaded_irq (unsigned int irq, irq_handler_t handler,irq_handler_t thread_fn, unsigned long irqflags, const char *devname, void *dev_id);

参数

1. irq-分配中断线
2. handler-发生IRQ时要调用的函数.线程中断的主处理程序如果NULL和thread_fn！= NULL，则安装默认的主处理程序
3. thread_fn-从irq处理程序线程调用的函数如果为NULL，则不创建任何irq线程
4. irqflags-中断类型标志
5. devname-声明设备的ASCII名称
6. dev_id-将Cookie传递回处理程序函数

Handler和Thread_fn参数令人困惑.此外，驱动程序中未定义任何工作功能.

the Handler and Thread_fn arguments are the ones which are confusing. Also there is no work function defined in the driver.

这里是我所指的驱动程序.

有人可以帮助我理解这一点吗?

Can somebody help me in understanding this?

推荐答案

添加了request_threaded_irq()函数，以允许开发人员将中断处理代码分为两部分.一部分将在中断被阻止的情况下执行，另一部分可以由内核线程在不中断被阻止的情况下完成.有关原因的详细信息，您可以阅读以下内容:

The request_threaded_irq() function was added to allow developers to split interrupt handling code into two parts. One part that will execute with interrupts blocked, and a second part that can be done by a kernel thread without interrupts blocked. For details of why, you can read this:

http://lwn.net/Articles/302043/

以您为例，您链接到的驱动程序将执行以下操作:

In your case, the driver you linked to does this:

err = request_threaded_irq(client->irq, NULL, cy8ctmg110_irq_thread,
                           IRQF_TRIGGER_RISING, "touch_reset_key", ts);

在检测到中断时，将通过为第二个arg，处理程序，thread_fn的参数或函数cy8ctmg110_irq_thread()传递NULL来调用

By passing NULL for the second arg, "handler", the argument to thread_fn, or the function cy8ctmg110_irq_thread() will be called when the interrupt is detected.

对于您来说，选择哪个请求irq函数将取决于您的驱动程序在中断上下文中需要执行的操作.

For you, choosing which request irq function will depend on what your driver needs to do in interrupt context.

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