Index: /branches/libffado-2.0/src/libieee1394/ieee1394service.cpp
===================================================================
--- /branches/libffado-2.0/src/libieee1394/ieee1394service.cpp (revision 1371)
+++ /branches/libffado-2.0/src/libieee1394/ieee1394service.cpp (revision 1372)
@@ -292,6 +292,6 @@
         }
     }
-    
-    // check state
+
+    // init helpers
     if(!m_pCTRHelper) {
         debugFatal("No CycleTimerHelper available, bad!\n");
@@ -309,4 +309,7 @@
     }
     m_pIsoManager->setVerboseLevel(getDebugLevel());
+
+    m_pIsoManager->setReceiveMode(RAW1394_DMA_PACKET_PER_BUFFER);
+
     if(!m_pIsoManager->init()) {
         debugFatal("Could not initialize IsoHandlerManager\n");
Index: /branches/libffado-2.0/src/libieee1394/IsoHandlerManager.cpp
===================================================================
--- /branches/libffado-2.0/src/libieee1394/IsoHandlerManager.cpp (revision 1345)
+++ /branches/libffado-2.0/src/libieee1394/IsoHandlerManager.cpp (revision 1372)
@@ -459,4 +459,5 @@
    , m_IsoThreadReceive ( NULL )
    , m_IsoTaskReceive ( NULL )
+   , m_receive_mode( RAW1394_DMA_PACKET_PER_BUFFER )
 {
 }
@@ -470,4 +471,5 @@
    , m_IsoThreadReceive ( NULL )
    , m_IsoTaskReceive ( NULL )
+   , m_receive_mode( RAW1394_DMA_PACKET_PER_BUFFER )
 {
 }
@@ -777,11 +779,18 @@
         // the receive buffer size doesn't matter for the latency,
         // but it has a minimal value in order for libraw to operate correctly (300)
-        int buffers=400;
+        int buffers=1;
+        while(buffers < (int)packets_per_period && buffers < MAX_RECV_NB_BUFFERS) {
+            buffers *= 2;
+        }
+
+        // ensure at least 2 hardware interrupts per ISO buffer wraparound
+        if(irq_interval > buffers/2) {
+            irq_interval = buffers/2;
+        }
 
         // create the actual handler
+        debugOutput( DEBUG_LEVEL_VERBOSE, " creating IsoRecvHandler\n");
         h = new IsoHandler(*this, IsoHandler::eHT_Receive,
                            buffers, max_packet_size, irq_interval);
-
-        debugOutput( DEBUG_LEVEL_VERBOSE, " creating IsoRecvHandler\n");
 
         if(!h) {
@@ -790,16 +799,10 @@
         }
 
+        h->setReceiveMode(m_receive_mode);
+
     } else if (stream->getType()==StreamProcessor::ePT_Transmit) {
         // setup the optimal parameters for the raw1394 ISO buffering
-//        unsigned int packets_per_period = stream->getPacketsPerPeriod();
         unsigned int max_packet_size = stream->getMaxPacketSize();
-//         unsigned int page_size = getpagesize();
-
-        // Ensure we don't request a packet size bigger than the
-        // kernel-enforced maximum which is currently 1 page.
-//         if (max_packet_size > page_size) {
-//             debugError("max packet size (%u) > page size (%u)\n", max_packet_size, page_size);
-//             return false;
-//         }
+
         if (max_packet_size > MAX_XMIT_PACKET_SIZE) {
             debugError("max packet size (%u) > MAX_XMIT_PACKET_SIZE (%u)\n",
@@ -809,13 +812,14 @@
 
         // the SP specifies how many packets to ISO-buffer
-        int buffers = stream->getNbPacketsIsoXmitBuffer();
-        if (buffers > MAX_XMIT_NB_BUFFERS) {
-            debugOutput(DEBUG_LEVEL_VERBOSE,
-                        "nb buffers (%u) > MAX_XMIT_NB_BUFFERS (%u)\n",
-                        buffers, MAX_XMIT_NB_BUFFERS);
-            buffers = MAX_XMIT_NB_BUFFERS;
-        }
-        unsigned int irq_interval = buffers / MINIMUM_INTERRUPTS_PER_PERIOD;
-        if(irq_interval <= 0) irq_interval=1;
+        int req_buffers = stream->getNbPacketsIsoXmitBuffer();
+        int buffers=1; 
+        while(buffers < (int)req_buffers && buffers < MAX_RECV_NB_BUFFERS) {
+            buffers *= 2;
+        }
+
+        int irq_interval = req_buffers / MINIMUM_INTERRUPTS_PER_PERIOD;
+        if(irq_interval <= 0) irq_interval = 1;
+        // ensure at least 2 hardware interrupts per ISO buffer wraparound
+        if(irq_interval > buffers/2) irq_interval = buffers/2;
 
         debugOutput( DEBUG_LEVEL_VERBOSE, " creating IsoXmitHandler\n");
Index: /branches/libffado-2.0/src/libieee1394/IsoHandlerManager.h
===================================================================
--- /branches/libffado-2.0/src/libieee1394/IsoHandlerManager.h (revision 1292)
+++ /branches/libffado-2.0/src/libieee1394/IsoHandlerManager.h (revision 1372)
@@ -197,4 +197,12 @@
          */
         bool handleBusReset();
+
+        /**
+         * @brief set iso receive mode. doesn't have any effect if the stream is running
+         * @param m receive mode
+         */
+        void setReceiveMode(enum raw1394_iso_dma_recv_mode m)
+            {m_receive_mode = m;}
+
     // the state machine
     private:
@@ -236,4 +244,5 @@
         Util::Thread *  m_IsoThreadReceive;
         IsoTask *       m_IsoTaskReceive;
+        enum raw1394_iso_dma_recv_mode m_receive_mode;
 
         // debug stuff
Index: /branches/libffado-2.0/src/libieee1394/IsoHandler.cpp
===================================================================
--- /branches/libffado-2.0/src/libieee1394/IsoHandler.cpp (revision 1345)
+++ /branches/libffado-2.0/src/libieee1394/IsoHandler.cpp (revision 1372)
@@ -81,4 +81,5 @@
    , m_last_now( 0xFFFFFFFF )
    , m_last_packet_handled_at( 0xFFFFFFFF )
+   , m_receive_mode ( RAW1394_DMA_PACKET_PER_BUFFER )
    , m_Client( 0 )
    , m_speed( RAW1394_ISO_SPEED_400 )
@@ -106,4 +107,5 @@
    , m_last_now( 0xFFFFFFFF )
    , m_last_packet_handled_at( 0xFFFFFFFF )
+   , m_receive_mode ( RAW1394_DMA_PACKET_PER_BUFFER )
    , m_Client( 0 )
    , m_speed( RAW1394_ISO_SPEED_400 )
@@ -131,4 +133,5 @@
    , m_last_now( 0xFFFFFFFF )
    , m_last_packet_handled_at( 0xFFFFFFFF )
+   , m_receive_mode ( RAW1394_DMA_PACKET_PER_BUFFER )
    , m_Client( 0 )
    , m_speed( speed )
@@ -675,7 +678,7 @@
                                 m_max_packet_size,
                                 m_Client->getChannel(),
-                                RAW1394_DMA_PACKET_PER_BUFFER,
+                                m_receive_mode,
                                 m_irq_interval)) {
-            debugFatal("Could not do receive initialisation (DMA_BUFFERFILL)!\n" );
+            debugFatal("Could not do receive initialisation!\n" );
             debugFatal("  %s\n",strerror(errno));
             return false;
Index: /branches/libffado-2.0/src/libieee1394/IsoHandler.h
===================================================================
--- /branches/libffado-2.0/src/libieee1394/IsoHandler.h (revision 1343)
+++ /branches/libffado-2.0/src/libieee1394/IsoHandler.h (revision 1372)
@@ -168,4 +168,11 @@
     uint32_t getLastPacketTime() {return m_last_packet_handled_at;};
 
+    /**
+     * @brief set iso receive mode. doesn't have any effect if the stream is running
+     * @param m receive mode
+     */
+    void setReceiveMode(enum raw1394_iso_dma_recv_mode m)
+        {m_receive_mode = m;}
+
     void notifyOfDeath();
     bool handleBusReset();
@@ -181,4 +188,5 @@
     uint32_t        m_last_now;
     uint32_t        m_last_packet_handled_at;
+    enum raw1394_iso_dma_recv_mode m_receive_mode;
 
     Streaming::StreamProcessor *m_Client; // FIXME: implement with functors
Index: /branches/libffado-2.0/config.h.in
===================================================================
--- /branches/libffado-2.0/config.h.in (revision 1371)
+++ /branches/libffado-2.0/config.h.in (revision 1372)
@@ -133,5 +133,6 @@
 // due to weirdness in the kernel layer
 #define MAX_XMIT_PACKET_SIZE                         (2048-16)
-#define MAX_XMIT_NB_BUFFERS                                200
+#define MAX_XMIT_NB_BUFFERS                                128
+#define MAX_RECV_NB_BUFFERS                                128
 
 // should be PAGE_SIZE (4096) for unpatched kernels