osmosdr/rtl/miri/hackrf: use 15 buffers by default

folowing rtl-sdr commit 89f73b183f2dac9c0dd75beca4cf2f77f20c4a36

So far we had 32 * 256KB which was a bit overkill, 15 are more than
enough.

15 was chosen instead of 16 because at least on Linux there seems to be
a system-wide limit of 63 transfers (when they are 256KB large), so 4
dongles can be used on a single machine without lowering the default
transfer number.

lib/hackrf/hackrf_sink_c.cc

@@ -51,7 +51,7 @@
 using namespace boost::assign;
 
 #define BUF_LEN  (16 * 32 * 512) /* must be multiple of 512 */
-#define BUF_NUM   32
+#define BUF_NUM   15
 
 #define BYTES_PER_SAMPLE  2 /* HackRF device consumes 8 bit unsigned IQ data */
 

lib/hackrf/hackrf_source_c.cc

@@ -45,7 +45,7 @@
 using namespace boost::assign;
 
 #define BUF_LEN  (16 * 32 * 512) /* must be multiple of 512 */
-#define BUF_NUM   32
+#define BUF_NUM   15
 
 #define BYTES_PER_SAMPLE  2 /* HackRF device produces 8 bit unsigned IQ data */
 

lib/miri/miri_source_c.cc

@@ -45,7 +45,7 @@
 using namespace boost::assign;
 
 #define BUF_SIZE  2304 * 8 * 2
-#define BUF_NUM   32
+#define BUF_NUM   15
 #define BUF_SKIP  1 // buffers to skip due to garbage
 
 #define BYTES_PER_SAMPLE  4 // mirisdr device delivers 16 bit signed IQ data
@@ -210,7 +210,7 @@ void miri_source_c::_mirisdr_wait(miri_source_c *obj)
 
 void miri_source_c::mirisdr_wait()
 {
-  int ret = mirisdr_read_async( _dev, _mirisdr_callback, (void *)this, 0, BUF_SIZE );
+  int ret = mirisdr_read_async( _dev, _mirisdr_callback, (void *)this, _buf_num, BUF_SIZE );
 
   _running = false;
 

lib/osmosdr/osmosdr_src_c.cc

@@ -44,7 +44,7 @@
 using namespace boost::assign;
 
 #define BUF_LEN  (16 * 32 * 512) /* must be multiple of 512 */
-#define BUF_NUM   32
+#define BUF_NUM   15
 #define BUF_SKIP  1 // buffers to skip due to garbage
 
 #define BYTES_PER_SAMPLE  4 // osmosdr device delivers 16 bit signed IQ data
@@ -203,7 +203,7 @@ void osmosdr_src_c::_osmosdr_wait(osmosdr_src_c *obj)
 
 void osmosdr_src_c::osmosdr_wait()
 {
-  int ret = osmosdr_read_async( _dev, _osmosdr_callback, (void *)this, 0, _buf_len );
+  int ret = osmosdr_read_async( _dev, _osmosdr_callback, (void *)this, _buf_num, _buf_len );
 
   _running = false;
 

lib/rtl/rtl_source_c.cc

@@ -46,7 +46,7 @@
 using namespace boost::assign;
 
 #define BUF_LEN  (16 * 32 * 512) /* must be multiple of 512 */
-#define BUF_NUM   32
+#define BUF_NUM   15
 #define BUF_SKIP  1 // buffers to skip due to initial garbage
 
 #define BYTES_PER_SAMPLE  2 // rtl device delivers 8 bit unsigned IQ data
@@ -301,7 +301,7 @@ void rtl_source_c::_rtlsdr_wait(rtl_source_c *obj)
 
 void rtl_source_c::rtlsdr_wait()
 {
-  int ret = rtlsdr_read_async( _dev, _rtlsdr_callback, (void *)this, 0, _buf_len );
+  int ret = rtlsdr_read_async( _dev, _rtlsdr_callback, (void *)this, _buf_num, _buf_len );
 
   _running = false;