/* ctlchurn.c — control: same topology, but ONLY write sizes that are exact
 * multiples of both aligns (12 and 14): lcm = 84 -> 43008, 21504. */
#include <sys/soundcard.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <unistd.h>

int
main(int argc, char **argv)
{
	int fds[2], ch[2] = { 6, 7 }, fmt = AFMT_S16_LE, sp = 48000, r, i, j;
	static const int sz[] = { 43008, 43008, 21504, 43008 };
	unsigned char b[131072];
	long it = (argc > 1) ? atol(argv[1]) : 300;

	memset(b, 1, sizeof(b));
	for (i = 0; i < 2; i++) {
		fds[i] = open("/dev/dsp", O_WRONLY);
		if (fds[i] < 0) { perror("open"); return (1); }
		ioctl(fds[i], SNDCTL_DSP_SETFMT, &fmt);
		ioctl(fds[i], SNDCTL_DSP_SPEED, &sp);
		ioctl(fds[i], SNDCTL_DSP_CHANNELS, &ch[i]);
	}
	for (j = 0; j < it; j++)
		for (i = 0; i < 2; i++) {
			r = write(fds[i], b, sz[j % 4]);
			if (r < 0) { perror("write"); return (1); }
			usleep(3000);
		}
	printf("control done, no error\n");
	return (0);
}