Index: uspace/lib/drv/generic/remote_audio_pcm.c
===================================================================
--- uspace/lib/drv/generic/remote_audio_pcm.c	(revision 57e8b3ba054d7a008b430e7b6b67994b03197240)
+++ uspace/lib/drv/generic/remote_audio_pcm.c	(revision eceb300f1af5b2c6d6ef5514075ff83891dc86a0)
@@ -45,4 +45,5 @@
 typedef enum {
 	IPC_M_AUDIO_PCM_GET_INFO_STR,
+	IPC_M_AUDIO_PCM_TEST_FORMAT,
 	IPC_M_AUDIO_PCM_GET_BUFFER,
 	IPC_M_AUDIO_PCM_RELEASE_BUFFER,
@@ -106,4 +107,33 @@
 }
 
+int audio_pcm_test_format(audio_pcm_sess_t *sess, unsigned *channels,
+    unsigned *rate, pcm_sample_format_t *format)
+{
+	async_exch_t *exch = async_exchange_begin(sess);
+	sysarg_t channels_arg = channels ? *channels : 0;
+	sysarg_t rate_arg = rate ? *rate : 0;
+	sysarg_t format_arg = format ? *format : 0;
+	const int ret = async_req_4_3(exch,
+	    DEV_IFACE_ID(AUDIO_PCM_BUFFER_IFACE),
+	    IPC_M_AUDIO_PCM_TEST_FORMAT, channels_arg, rate_arg, format_arg,
+	    &channels_arg, &rate_arg, &format_arg);
+	async_exchange_end(exch);
+
+	/* All OK or something has changed. Verify that it was not one of the
+	 * params we care about */
+	if ((ret == EOK || ret == ELIMIT)
+	    && (!channels || *channels == channels_arg)
+	    && (!rate || *rate == rate_arg)
+	    && (!format || *format == format_arg))
+		return EOK;
+	if (channels)
+		*channels = channels_arg;
+	if (rate)
+		*rate = rate_arg;
+	if (format)
+		*format = format_arg;
+	return ret;
+}
+
 int audio_pcm_get_buffer(audio_pcm_sess_t *sess, void **buffer, size_t *size,
     async_client_conn_t event_rec, void* arg)
@@ -202,4 +232,5 @@
  */
 static void remote_audio_pcm_get_info_str(ddf_fun_t *, void *, ipc_callid_t, ipc_call_t *);
+static void remote_audio_pcm_test_format(ddf_fun_t *, void *, ipc_callid_t, ipc_call_t *);
 static void remote_audio_pcm_get_buffer(ddf_fun_t *, void *, ipc_callid_t, ipc_call_t *);
 static void remote_audio_pcm_release_buffer(ddf_fun_t *, void *, ipc_callid_t, ipc_call_t *);
@@ -212,4 +243,5 @@
 static remote_iface_func_ptr_t remote_audio_pcm_iface_ops[] = {
 	[IPC_M_AUDIO_PCM_GET_INFO_STR] = remote_audio_pcm_get_info_str,
+	[IPC_M_AUDIO_PCM_TEST_FORMAT] = remote_audio_pcm_test_format,
 	[IPC_M_AUDIO_PCM_GET_BUFFER] = remote_audio_pcm_get_buffer,
 	[IPC_M_AUDIO_PCM_RELEASE_BUFFER] = remote_audio_pcm_release_buffer,
@@ -254,4 +286,15 @@
 		async_data_read_finalize(name_id, name, name_size);
 	}
+}
+
+static void remote_audio_pcm_test_format(ddf_fun_t *fun, void *iface, ipc_callid_t callid, ipc_call_t *call)
+{
+	const audio_pcm_iface_t *pcm_iface = iface;
+	unsigned channels = DEV_IPC_GET_ARG1(*call);
+	unsigned rate = DEV_IPC_GET_ARG2(*call);
+	pcm_sample_format_t format = DEV_IPC_GET_ARG3(*call);
+	const int ret = pcm_iface->test_format ?
+	    pcm_iface->test_format(fun, &channels, &rate, &format) : ENOTSUP;
+	async_answer_3(callid, ret, channels, rate, format);
 }
 
Index: uspace/lib/drv/include/audio_pcm_iface.h
===================================================================
--- uspace/lib/drv/include/audio_pcm_iface.h	(revision 57e8b3ba054d7a008b430e7b6b67994b03197240)
+++ uspace/lib/drv/include/audio_pcm_iface.h	(revision eceb300f1af5b2c6d6ef5514075ff83891dc86a0)
@@ -58,4 +58,7 @@
 
 int audio_pcm_get_info_str(audio_pcm_sess_t *, const char **);
+int audio_pcm_test_format(audio_pcm_sess_t *, unsigned *, unsigned *,
+    pcm_sample_format_t *);
+
 int audio_pcm_get_buffer(audio_pcm_sess_t *, void **, size_t *,
     async_client_conn_t, void *);
@@ -73,4 +76,6 @@
 typedef struct {
 	int (*get_info_str)(ddf_fun_t *, const char **);
+	int (*test_format)(ddf_fun_t *, unsigned *, unsigned *,
+	    pcm_sample_format_t *);
 	int (*get_buffer)(ddf_fun_t *, void **, size_t *);
 	int (*release_buffer)(ddf_fun_t *);