我今天开始试了下带异步通知的button的驱动，发现一个问题，我的测试程序执行时会出现一堆的信息，第一次看到不知道时什么东西，看看师兄们是不是看到过
下面是出现的串口信息：
Not tainted (2.6.22.6 #84)00b0 00020001 0000001d 00000037 30023
pc : [<c0091884>] lr : [<c04ef03c>] psr: 20000093IRQs off FIQs on Mode
5e80: 41129200 30023480 c0315e
sp : c3efdf30 ip : c071d174 fp : c3efdf50013Control: c000717f Table: 33d48000
r7 : 00000001 r6 : c3d10d40 r5 : 00000000 r4 : c071d174
r3 : a0000093 r2 : c3cae438 r1 : 3159454b r0 : c3cae438
Flags: nzCv IRQs off FIQs on Mode SVC_32 Segment user
Control: c000717f Table: 33ef0000 DAC: 00000015
Process button_test (pid: 767, stack limit = 0xc3efc258)
Stack: (0xc3efdf30 to 0xc3efe000)
df20: c3d10d40 00000000 00002002 00000003
df40: 00000003 c3efdf60 c3efdf54 bf000148 c009181c c3efdf80 c3efdf64 c00914dc
df60: bf000140 00000004 fffffff7 00002002 c3d10d40 c3efdfa4 c3efdf84 c009165c
df80: c00912bc 00002002 00002002 00000004 000000dd c002e004 00000000 c3efdfa8
dfa0: c002de60 c00915f4 00002002 00002002 00000003 00000004 00002002 00000000
dfc0: 00002002 00002002 00000004 00000003 bea6fed4 00008220 00008604 bea6fcd8
dfe0: 00000000 bea6fc6c 0000fe18 0000fb88 60000010 00000003 6f6f7473 72632f6c
Backtrace:
Function entered at [<c009180c>] from [<bf000148>]
r8:00000003 r7:00000003 r6:00002002 r5:00000000 r4:c3d10d40
Function entered at [<bf000130>] from [<c00914dc>]
Function entered at [<c00912ac>] from [<c009165c>]
r7:c3d10d40 r6:00002002 r5:fffffff7 r4:00000004
Function entered at [<c00915e4>] from [<c002de60>]
r8:c002e004 r7:000000dd r6:00000004 r5:00002002 r4:00002002
Code: e5941000 e1a0c004 e3510000 0a00000e (e591300c)
Segmentation fault
这时什么东西啊？
我的测试程序如下：
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <unistd.h>
#include <signal.h>
char buff_r;int fd;
void input_handler(int signum)
{
int i;
read(fd,buff_r,1);
printf("the keynum is,signalnum:%d\n",signum);
printf("\n\n");
}
main()
{
int fd;
int oflags;
int err;
fd=open("/dev/buttons", O_RDWR , S_IRUSR | S_IWUSR);
if(fd!= -1)
{
printf("the buttons open ok!\n");
signal(SIGIO, input_handler);
fcntl(fd, F_SETOWN,getpid());
oflags = fcntl(fd, F_GETFL);
fcntl(fd,F_SETFL,oflags|FASYNC);
while(1) {
printf("entry to sleep\n");
sleep(100);
}
}
else
printf("device open failed\n");
}
