Disable icom_get_vfo as user twiddling VFO knob does not work while polling

current_vfo is still determined at startup
 https://github.com/Hamlib/Hamlib/issues/806

rigs/icom/icom.c

@@ -967,10 +967,6 @@ icom_rig_open(RIG *rig)
             rig_debug(RIG_DEBUG_ERR, "%s: Unable to determine USB echo status\n", __func__);
             RETURNFUNC(retval);
         }
-
-        // Determine active vfo again since it would have failed the 1st time
-        rig->state.current_vfo = icom_current_vfo(rig);
-        icom_current_vfo(rig);
     }
 
     rig->state.current_vfo = icom_current_vfo(rig);
@@ -1736,8 +1732,13 @@ int icom_set_xit_new(RIG *rig, vfo_t vfo, shortfreq_t ts)
 
     Has been tested for IC-746pro,  Should work on the all dsp rigs ie pro models.
     The 746 documentation says it has the get_if_filter, but doesn't give any decoding information ? Please test.
+
+   DSP filter setting ($1A$03), but not supported by every rig,
+   and some models like IC910/Omni VI Plus have a different meaning for
+   this subcommand
 */
    
+
 pbwidth_t icom_get_dsp_flt(RIG *rig, rmode_t mode)
 {
 
@@ -1751,6 +1752,9 @@ pbwidth_t icom_get_dsp_flt(RIG *rig, rmode_t mode)
     rig_debug(RIG_DEBUG_VERBOSE, "%s called, mode=%s\n", __func__,
               rig_strrmode(mode));
 
+    // only these models that we know of -- keep set_dsp_flt in sync
+    if ((rig->caps->rig_model & (RIG_MODEL_IC7000 | RIG_MODEL_IC7800 | RIG_MODEL_IC7300 || RIG_MODEL_IC9700 || RIG_MODEL_IC7610)) == 0) RETURNFUNC(RIG_OK);
+
     if (rig_has_get_func(rig, RIG_FUNC_RF)
             && (mode & (RIG_MODE_RTTY | RIG_MODE_RTTYR)))
     {
@@ -1831,6 +1835,9 @@ int icom_set_dsp_flt(RIG *rig, rmode_t mode, pbwidth_t width)
 
     ENTERFUNC;
 
+    // only these models that we know of -- keep get_dsp in sync here
+    if ((rig->caps->rig_model & (RIG_MODEL_IC7000 | RIG_MODEL_IC7800 | RIG_MODEL_IC7300 || RIG_MODEL_IC9700 || RIG_MODEL_IC7610)) == 0) RETURNFUNC(RIG_OK);
+
     if (RIG_PASSBAND_NOCHANGE == width)
     {
         RETURNFUNC(RIG_OK);
@@ -2238,14 +2245,7 @@ int icom_set_mode(RIG *rig, vfo_t vfo, rmode_t mode, pbwidth_t width)
         RETURNFUNC(-RIG_ERJCTED);
     }
 
-    /* DSP filter setting ($1A$03), but not supported by every rig,
-     * and some models like IC910/Omni VI Plus have a different meaning for
-     * this subcommand
-     */
-    if (rig->caps->rig_model == RIG_MODEL_IC7000)
-    {
     icom_set_dsp_flt(rig, mode, width);
-    }
 
     RETURNFUNC(RIG_OK);
 }
@@ -2552,6 +2552,9 @@ int icom_get_mode(RIG *rig, vfo_t vfo, rmode_t *mode, pbwidth_t *width)
     RETURNFUNC(RIG_OK);
 }
 
+#if 0
+// this seems to work but not for cqrlog and user twiddling VFO knob.
+// may be able to use twiddle but will disable for now
 /*
  * icom_get_vfo
  * Assumes rig!=NULL, rig->state.priv!=NULL
@@ -2564,6 +2567,7 @@ int icom_get_vfo(RIG *rig, vfo_t *vfo)
 
     RETURNFUNC(RIG_OK);
 }
+#endif
 
 /*
  * icom_set_vfo

rigs/icom/icom.h

@@ -30,7 +30,7 @@
 #include <sys/time.h>
 #endif
 
-#define BACKEND_VER "20210928"
+#define BACKEND_VER "20210929"
 
 #define ICOM_IS_SECONDARY_VFO(vfo) ((vfo) & (RIG_VFO_B | RIG_VFO_SUB | RIG_VFO_SUB_B | RIG_VFO_MAIN_B))
 #define ICOM_GET_VFO_NUMBER(vfo) (ICOM_IS_SECONDARY_VFO(vfo) ? 0x01 : 0x00)
@@ -308,7 +308,11 @@ int icom_set_mode(RIG *rig, vfo_t vfo, rmode_t mode, pbwidth_t width);
 int icom_get_mode_with_data(RIG *rig, vfo_t vfo, rmode_t *mode,
                             pbwidth_t *width);
 int icom_get_mode(RIG *rig, vfo_t vfo, rmode_t *mode, pbwidth_t *width);
+#if 0 // see icom_get_vfo in icom.c
 int icom_get_vfo(RIG *rig, vfo_t *vfo);
+#else
+#define icom_get_vfo NULL
+#endif
 int icom_set_vfo(RIG *rig, vfo_t vfo);
 int icom_set_rptr_shift(RIG *rig, vfo_t vfo, rptr_shift_t rptr_shift);
 int icom_get_rptr_shift(RIG *rig, vfo_t vfo, rptr_shift_t *rptr_shift);