Improve mixer control protocol to avoid deadlock

lib_xua/src/core/endpoint0/xua_ep0_uacreqs.xc

@@ -155,6 +155,8 @@ static void updateMasterVol(int unitID, chanend ?c_mix_ctl)
 #if (OUT_VOLUME_IN_MIXER)
                     if (!isnull(c_mix_ctl))
                     {
+                        outct(c_mix_ctl, XS1_CT_END);
+                        inct(c_mix_ctl);
                         outuint(c_mix_ctl, SET_MIX_OUT_VOL);
                         outuint(c_mix_ctl, i-1);
                         outuint(c_mix_ctl, x);
@@ -181,6 +183,8 @@ static void updateMasterVol(int unitID, chanend ?c_mix_ctl)
 #if (IN_VOLUME_IN_MIXER)
                     if (!isnull(c_mix_ctl))
                     {
+                        outct(c_mix_ctl, XS1_CT_END);
+                        inct(c_mix_ctl);
                         outuint(c_mix_ctl, SET_MIX_IN_VOL);
                         outuint(c_mix_ctl, i-1);
                         outuint(c_mix_ctl, x);
@@ -228,6 +232,8 @@ static void updateVol(int unitID, int channel, chanend ?c_mix_ctl)
 #if (OUT_VOLUME_IN_MIXER)
                 if (!isnull(c_mix_ctl))
                 {
+                    outct(c_mix_ctl, XS1_CT_END);
+                    inct(c_mix_ctl);
                     outuint(c_mix_ctl, SET_MIX_OUT_VOL);
                     outuint(c_mix_ctl, channel-1);
                     outuint(c_mix_ctl, x);
@@ -250,6 +256,8 @@ static void updateVol(int unitID, int channel, chanend ?c_mix_ctl)
 #if (IN_VOLUME_IN_MIXER)
                 if (!isnull(c_mix_ctl))
                 {
+                    outct(c_mix_ctl, XS1_CT_END);
+                    inct(c_mix_ctl);
                     outuint(c_mix_ctl, SET_MIX_IN_VOL);
                     outuint(c_mix_ctl, channel-1);
                     outuint(c_mix_ctl, x);
@@ -267,6 +275,8 @@ static void updateVol(int unitID, int channel, chanend ?c_mix_ctl)
 
 void UpdateMixerOutputRouting(chanend c_mix_ctl, unsigned map, unsigned dst, unsigned src)
 { 
+    outct(c_mix_ctl, XS1_CT_END);
+    inct(c_mix_ctl);
     outuint(c_mix_ctl, map);
     outuint(c_mix_ctl, dst);
     outuint(c_mix_ctl, src);
@@ -275,6 +285,8 @@ void UpdateMixerOutputRouting(chanend c_mix_ctl, unsigned map, unsigned dst, uns
 
 void UpdateMixMap(chanend c_mix_ctl, int mix, int input, int src)
 {
+    outct(c_mix_ctl, XS1_CT_END);
+    inct(c_mix_ctl);
     outuint(c_mix_ctl, SET_MIX_MAP);
     outuint(c_mix_ctl, mix);                 /* Mix bus */
     outuint(c_mix_ctl, input);               /* Mixer input (cn) */
@@ -284,6 +296,8 @@ void UpdateMixMap(chanend c_mix_ctl, int mix, int input, int src)
 
 void UpdateMixerWeight(chanend c_mix_ctl, int mix, int index, unsigned mult)
 { 
+    outct(c_mix_ctl, XS1_CT_END);
+    inct(c_mix_ctl);
     outuint(c_mix_ctl, SET_MIX_MULT);
     outuint(c_mix_ctl, mix);
     outuint(c_mix_ctl, index);
@@ -1014,6 +1028,8 @@ int AudioClassRequests_2(XUD_ep ep0_out, XUD_ep ep0_in, USB_SetupPacket_t &sp, c
                                     {
                                         if (!isnull(c_mix_ctl))
                                         {
+                                            outct(c_mix_ctl, XS1_CT_END);
+                                            inct(c_mix_ctl);
                                             outuint(c_mix_ctl, GET_STREAM_LEVELS);
                                             outuint(c_mix_ctl, i);
                                             outct(c_mix_ctl, XS1_CT_END);
@@ -1029,6 +1045,8 @@ int AudioClassRequests_2(XUD_ep ep0_out, XUD_ep ep0_in, USB_SetupPacket_t &sp, c
                                     {
                                         if (!isnull(c_mix_ctl))
                                         {
+                                            outct(c_mix_ctl, XS1_CT_END);
+                                            inct(c_mix_ctl);
                                             outuint(c_mix_ctl, GET_INPUT_LEVELS);
                                             outuint(c_mix_ctl, (i - NUM_USB_CHAN_OUT));
                                             outct(c_mix_ctl, XS1_CT_END);
@@ -1051,6 +1069,8 @@ int AudioClassRequests_2(XUD_ep ep0_out, XUD_ep ep0_in, USB_SetupPacket_t &sp, c
                                 {
                                     if (!isnull(c_mix_ctl))
                                     {
+                                        outct(c_mix_ctl, XS1_CT_END);
+                                        inct(c_mix_ctl);
                                         outuint(c_mix_ctl, GET_OUTPUT_LEVELS);
                                         outuint(c_mix_ctl, i);
                                         outct(c_mix_ctl, XS1_CT_END);

lib_xua/src/core/mixer/mixer.xc

@@ -361,6 +361,7 @@ static void mixer1(chanend c_host, chanend c_mix_ctl, chanend c_mixer2)
 #endif
 #if (MAX_MIX_COUNT > 0) || (IN_VOLUME_IN_MIXER) || (OUT_VOLUME_IN_MIXER) || defined (LEVEL_METER_HOST) || defined(LEVEL_METER_LEDS)
     unsigned cmd;
+    unsigned char ct;
 #endif
     unsigned request = 0;
 
@@ -381,9 +382,18 @@ static void mixer1(chanend c_host, chanend c_mix_ctl, chanend c_mixer2)
 #if (MAX_MIX_COUNT > 0) || (IN_VOLUME_IN_MIXER) || (OUT_VOLUME_IN_MIXER) || defined (LEVEL_METER_HOST) || defined(LEVEL_METER_LEDS)
         select
         {
-            case inuint_byref(c_mix_ctl, cmd):
+            /* Check if EP0 intends to send us a control command */
+            case inct_byref(c_mix_ctl, ct):
             {
                 int mix, index, val;
+                
+                /* Handshake back to tell EP0 we are ready for an update */
+                outct(c_mix_ctl, XS1_CT_END);
+
+                /* Receive command from EP0 */
+                cmd = inuint(c_mix_ctl);
+
+                /* Interpret control command */
                 switch (cmd)
                 {
 #if (MAX_MIX_COUNT > 0)