“在向量XX处的意外的IRQ陷阱"指的是“在XX处的意外IRQ陷阱".在Beaglebone Black(Linux BBBW 4.14.71-ti-r80)上 [英] "unexpected IRQ trap at vector XX" on Beaglebone Black (Linux BBBW 4.14.71-ti-r80)

问题描述

我对beaglebone black的中断处理有问题.我已经编写了自己的内核模块和用户空间驱动程序的组合以访问gpios(另请参见 https://github.com/Terstegge/gpio-bbb ).使用较旧的内核，一切工作正常.使用最新的debian映像(内核4.14.71-ti-r80)，内核日志中出现错误:

I have a problem with interrupt processing on the beaglebone black. I have written my own combination of a kernel module and a user-space driver to have access to gpios (see also https://github.com/Terstegge/gpio-bbb). With older kernels, everything was working fine. Using the most recent debian image (kernel 4.14.71-ti-r80), I get errors in the kernel log:

[  461.028013] gpio_bbb: Device /dev/gpio_bbb registered
[  507.507335] gpio_bbb: Requesting GPIO #30
[  507.507370] Mode: f
[  507.507383] gpio_bbb: Requesting GPIO #49
[  507.507395] Mode: 37
[  507.507405] gpio_bbb: Requesting GPIO #15
[  507.507414] Mode: 37
[  507.507656] gpio_bbb: Using IRQ #77 for GPIO #49
[  507.507821] gpio_bbb: Using IRQ #78 for GPIO #15
[  571.511409] irq 77, desc: db1ad800, depth: 0, count: 0, unhandled: 0
[  571.511429] ->handle_irq():  c01ab7b0, 
[  571.511458] handle_bad_irq+0x0/0x2c0
[  571.511463] ->irq_data.chip(): dc122910, 
[  571.511476] 0xdc122910
[  571.511481] ->action(): dc454600
[  571.511487] ->action->handler(): bf4c904c, 
[  571.511514] gpio_irq_handler+0x0/0x34 [gpio_bbb]
[  571.511524]    IRQ_NOPROBE set
[  571.511532] unexpected IRQ trap at vector 4d

我要做的是以下操作:在模块代码中，我调用gpio_to_irq()以获取irq号，然后调用request_irq().这两个调用似乎都有效，因为它们没有报告错误代码(请参见上面的日志文件):

What I do is the following: In the module code I call gpio_to_irq() to get the irq number and then call request_irq(). Both calls seem to work, because they don't report an error code (see logfile above):

  /* request the irq and install handler */
  if (!irq_enabled[gpio_num]) {
    irq = gpio_to_irq(gpio_num);
    /* request irq and install handler */
    ret = request_irq (irq, gpio_irq_handler, IRQF_SHARED, "gpio_bbb", &gpio_data);
    if (ret != 0) {
      printk(KERN_ERR MOD_STR"Failed to request IRQ %i (error %i)\n", irq, ret);
      return ret;
    }
    printk(KERN_INFO MOD_STR"Using IRQ #%i for GPIO #%i\n", irq, gpio_num);
    irq_enabled[gpio_num] = irq;
  }

启动测试程序时，我可以看到我的模块(gpio_bbb)已针对/proc/interrupts中的中断注册:

When starting a test program I can see that my module (gpio_bbb) is registered for the interrupts in /proc/interrupts:

           CPU0       
...
 62:          0  tps65217   2 Edge      tps65217_pwr_but
 63:       5822  44e07000.gpio  29 Edge      wl18xx
 77:          0  4804c000.gpio  17 Edge      gpio_bbb
 78:          0  44e07000.gpio  15 Edge      gpio_bbb
IPI0:          0  CPU wakeup interrupts
IPI1:          0  Timer broadcast interrupts

在触发某些中断(gpio输入值更改)和(甚至)使用空中断处理程序触发时，它什么都不做:

When triggering some interrupts (gpio input value change) and (even) with an empty interrupt handler, which does nothing:

irqreturn_t gpio_irq_handler(int irq, void *dev_id) {
  return IRQ_HANDLED;
}

我在内核日志中收到以上错误消息，并且未处理我的中断:(我注意到中断号已更改(以前，gpio的irq编号为#gpio + 128).我也知道显然正在运行的新libgpiod中(我看到了/dev/gpiochip[0..3]设备)我的问题是否与这些更改有关? 我仍然有些困惑，因为我调用的所有方法似乎都可以正常工作，而且我的中断仍被处理为意外".我在做什么错??

I get the above error messages in the kernel log, and my interrupts are not processed :( I have noticed that the interrupt numbers have changed (formerly the irq number of a gpio was #gpio+128). I am also aware of the new libgpiod, which is obviously running (I see the /dev/gpiochip[0..3] devices). Are my problems related to these changes? Still I am a little bit confused because all the methods I call seem to work, and still my interrupts are handled as 'unexpected'. What am I doing wrong??

推荐答案

我已经更深入地研究了这个问题.简单的解决方案是在调用request_any_context_irq()之后添加irq_set_irq_type(irq, IRQ_TYPE_NONE)(现在应使用此方法代替request_irq()):

I have investigated the problem in more depth. The simple solution was to add a irq_set_irq_type(irq, IRQ_TYPE_NONE) after calling request_any_context_irq() (this method should now be used instead of request_irq()):

ret = request_any_context_irq (irq, _gpio_irq_handler, IRQF_SHARED, "gpio_bbb", &gpio_data);
if (ret < 0) {
  printk(KERN_ERR MOD_STR"Failed to request IRQ %i (error %i)\n", irq, ret);
  return ret;
}
// Set IRQ type
irq_set_irq_type(irq, IRQ_TYPE_NONE);

由于Linux中新的通用irq系统，这些更改似乎是必需的: https://www.kernel.org/doc/html/v4.12/core-api/genericirq.html .我还没有完全理解IRQ类型为何以及如何影响内部调用的方法，但是gpio模块又可以按预期工作.

These changes seem to be necessary becaue of the new generic irq system in linux: https://www.kernel.org/doc/html/v4.12/core-api/genericirq.html. I have not yet fully understood why and how the IRQ type influences the internally called methods, but the gpio module is working again as expected.

这篇关于“在向量XX处的意外的IRQ陷阱"指的是“在XX处的意外IRQ陷阱".在Beaglebone Black(Linux BBBW 4.14.71-ti-r80)上的文章就介绍到这了，希望我们推荐的答案对大家有所帮助，也希望大家多多支持IT屋！