/* The PCM pointer is only updated with period granularity */
if (snd_pcm_hw_params_is_batch(hwparams)) {
- pa_log_info("Disabling tsched mode since BATCH flag is set");
- _use_tsched = false;
+ bool is_usb = false;
+ const char *id;
+ snd_pcm_info_t* pcm_info;
+ snd_pcm_info_alloca(&pcm_info);
+
+ if (snd_pcm_info(pcm_handle, pcm_info) == 0 &&
+ (id = snd_pcm_info_get_id(pcm_info))) {
+ /* This horrible hack makes sure we don't disable tsched on USB
+ * devices, which have a low enough transfer size for timer-based
+ * scheduling to work. This can go away when the ALSA API supprots
+ * querying the block transfer size. */
+ if (pa_streq(id, "USB Audio"))
+ is_usb = true;
+ }
+
+ if (!is_usb) {
+ pa_log_info("Disabling tsched mode since BATCH flag is set");
+ _use_tsched = false;
+ }
}
#if (SND_LIB_VERSION >= ((1<<16)|(0<<8)|24)) /* API additions in 1.0.24 */