Messages in this thread | | | Date | Thu, 28 Jul 2005 08:43:16 -0400 | From | John Que <> | Subject | |
| |
Hello,
I want ,for tracing and debugging purposes, to be able to generate a single interrupt on a device which (unlike the timer or ide devices, for example) does not get interrupts very frequently.
Looking at the output of /proc/interrupts (and look at IRQ 6 of the floppy) shows that the floppy device interrupt counter is not incremented during time if you are not constatntly working with it.
So a good candidate for generating a single interrupt can be a floppy.
Is there a way to generate a single interrupt on a floppy device?
I had tried the following:
I mount the floppy; I see that during the time, sometimes after running ls on a floppy 2 interrupts are generated; and sometimes after ls on a floppy no interrupts are generated. The same is with creating a file/reading a file: sometimes there are interrupts and sometimes there are no interrupts.
So I wrote the following little program:
#define BUFFER_SIZE 2048
char buffer[BUFFER_SIZE] __attribute__((aligned(4096)));
int main() {
int fd; int bytes_read; int i; fd = open("/dev/fd0",O_DIRECT);
void* data;
if (fd < 0 ) printf("could not open device\n");
else
printf("device opened\n");
{ bytes_read = read(fd,buffer,512);
//fseek(fd,SEEK_CUR,1); printf("bytes_read = %d\n",bytes_read); }
close(fd); }
Each time I ran it I got course : device opened bytes_read = 512
But running this program again and again ***DOES NOT*** increase the number of interrupt on the floppy device IRQ (6).
Any ideas?
Which user space code I should write / Which operation should I do so that each time I will do it,(again and again) it will generate an interrupt on the floppy IRQ (6) ?
(BTW I build this program by gcc -D_GNU_SOURCE floppy.c)
Regards, John - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
| |