- if (request == SNDCTL_DSP_SPEED) {
- int ret, bsize, frag;
-
- // ~4ms. gpSP wants small buffers or else it stutters
- // because of it's audio thread sync stuff
- bsize = *arg / 250 * 4;
- for (frag = 0; bsize; bsize >>= 1, frag++)
- ;
-
- frag |= 16 << 16; // fragment count
- ret = ioctl(fd, SNDCTL_DSP_SETFRAGMENT, &frag);
- if (ret != 0) {
- err("snd ioctl SETFRAGMENT %08x: ", frag);
- perror(NULL);
+ switch(request) {
+ case SNDCTL_DSP_SETFRAGMENT: {
+ int ret, bsize, frag, frag_cnt;
+ if (arg == NULL)
+ break;
+
+ frag = *arg & 0xffff;
+ frag_cnt = *arg >> 16;
+ bsize = frag_cnt << frag;
+ if (frag < 10 || bsize < 4096*4 || bsize > 4096*4*2) {
+ /*
+ * ~4ms. gpSP wants small buffers or else it stutters
+ * because of it's audio thread sync stuff
+ * XXX: hardcoding, as low samplerates will result in small fragment size,
+ * which itself causes ALSA stall and hangs the program.
+ * Also some apps change samplerate without reopening /dev/dsp,
+ * which causes ALSA to reject SNDCTL_DSP_SETFRAGMENT.
+ */
+ bsize = 44100 / 250 * 4;
+
+ for (frag = 0; bsize; bsize >>= 1, frag++)
+ ;
+
+ frag_cnt = 16;
+ }
+
+ frag |= frag_cnt << 16;
+ ret = ioctl(fd, SNDCTL_DSP_SETFRAGMENT, &frag);
+ if (ret != 0) {
+ err("snd ioctl SETFRAGMENT %08x: ", frag);
+ perror(NULL);
+ }
+ // indicate success even if we fail (because of ALSA mostly),
+ // things like MikMod will bail out otherwise.
+ return 0;