【发布时间】：2019-03-09 12:47:34
【问题描述】：
我的问题是在“/dev/hidraw2”上打开一个蒸汽控制器，这有时会导致程序挂起。我最大的问题是我不知道在哪里报告这个问题，所以我希望有人知道去哪里解决这个问题。
问题：
我有一个正在运行的 Arch Linux，它有一个连接到它的蒸汽控制器（与提供的加密狗连接）。
当试图通过打开'/dev/hidraw2'来访问设备时，我的程序卡在了“open”调用中。我的程序就是不返回。也无法用kill -9 杀死它。恢复的唯一方法是重新启动我的机器。
我将有问题的代码简化为：
// compiled with gcc main.c
#include <stdio.h>
#include <unistd.h>
#include <sys/ioctl.h>
#include <fcntl.h>
int main() {
for(;;) {
printf("opening steam controller\n");
# It doesn't return from the following open
int fd = open("/dev/hidraw2", O_RDWR | O_NONBLOCK | O_CLOEXEC);
printf("closing steam controller\n");
if (fd != -1) {
close(fd);
}
usleep(100000);
}
return 0;
}
要重现，您必须插入蒸汽控制器加密狗，启动上述程序，然后打开蒸汽控制器（它不会每次都挂起，因此您可能需要关闭控制器并重新打开）。
关于我的机器的更多信息：
$ uname -a
Linux schenker 4.20.7-arch1-1-ARCH #1 SMP PREEMPT Wed Feb 6 18:42:40 UTC 2019 x86_64 GNU/Linux
$ gcc --version
gcc (GCC) 8.2.1 20181127
如何进一步调查此问题？我必须深入了解蒸汽控制器驱动程序吗？还是 hidraw 层的更多问题？
更新：
请求dmesg 输出。重现错误需要 3 次尝试。我似乎注意到了可疑之处：
[ 141.161817] hid-steam 0003:28DE:1142.0002: Steam Controller 'XXXXXXXXXX' connected
[ 141.163527] input: Wireless Steam Controller as /devices/pci0000:00/0000:00:14.0/usb2/2-1/2-1:1.1/0003:28DE:1142.0002/input/input34
[ 151.291873] input: Wireless Steam Controller as /devices/pci0000:00/0000:00:14.0/usb2/2-1/2-1:1.1/0003:28DE:1142.0002/input/input35
[ 152.940759] input: Wireless Steam Controller as /devices/pci0000:00/0000:00:14.0/usb2/2-1/2-1:1.1/0003:28DE:1142.0002/input/input36
[ 155.287349] input: Wireless Steam Controller as /devices/pci0000:00/0000:00:14.0/usb2/2-1/2-1:1.1/0003:28DE:1142.0002/input/input37
[ 160.634001] hid-steam 0003:28DE:1142.0002: Steam Controller 'XXXXXXXXXX' disconnected
[ 172.665613] hid-steam 0003:28DE:1142.0002: Steam Controller 'XXXXXXXXXX' connected
[ 172.667006] input: Wireless Steam Controller as /devices/pci0000:00/0000:00:14.0/usb2/2-1/2-1:1.1/0003:28DE:1142.0002/input/input38
[ 181.306918] hid-steam 0003:28DE:1142.0002: Steam Controller 'XXXXXXXXXX' disconnected
[ 185.465807] hid-steam 0003:28DE:1142.0002: Steam Controller 'XXXXXXXXXX' connected
[ 185.467249] input: Wireless Steam Controller as /devices/pci0000:00/0000:00:14.0/usb2/2-1/2-1:1.1/0003:28DE:1142.0002/input/input39
[ 187.030851] input: Wireless Steam Controller as /devices/pci0000:00/0000:00:14.0/usb2/2-1/2-1:1.1/0003:28DE:1142.0002/input/input40
[ 192.673722] hid-steam 0003:28DE:1142.0002: Steam Controller 'XXXXXXXXXX' disconnected
[ 196.937743] hid-steam 0003:28DE:1142.0002: Steam Controller 'XXXXXXXXXX' connected
[ 196.939272] input: Wireless Steam Controller as /devices/pci0000:00/0000:00:14.0/usb2/2-1/2-1:1.1/0003:28DE:1142.0002/input/input41
更新2 还有一些 strace 输出：
openat(AT_FDCWD, "/dev/hidraw1", O_RDWR|O_NONBLOCK|O_CLOEXEC) = 3
write(1, "closing steam controller /dev/hi"..., 38closing steam controller /dev/hidraw1
) = 38
close(3) = 0
nanosleep({tv_sec=0, tv_nsec=100000000}, NULL) = 0
write(1, "opening steam controller /dev/hi"..., 38opening steam controller /dev/hidraw1
) = 38
openat(AT_FDCWD, "/dev/hidraw1", O_RDWR|O_NONBLOCK|O_CLOEXEC
这个问题不仅限于hidraw2，也可能发生在hidraw1上（我猜这取决于实际的steam控制器连接到哪里）
我还注意到，当我的程序卡住并且我在另一个控制台上调用启动第二个实例时，它会立即挂在 open() 上，与控制器的关闭/开启状态无关。
【问题讨论】：
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dmesg 说什么？
标签： c linux controller steam