mISDN: Add feature via MISDN_CTRL_FILL_EMPTY to fill fifo if empty

This prevents underrun of fifo when filled and in case of an underrun it
prevents subsequent underruns due to jitter.
Improve dsp, so buffers are kept filled with a certain delay, so moderate
jitter will not cause underrun all the time -> the audio quality is highly
improved. tones are not interrupted by gaps anymore, except when CPU is
stalling or in high load.

Signed-off-by: Andreas Eversberg <andreas@eversberg.eu>
Signed-off-by: Karsten Keil <kkeil@suse.de>

2 files changed, 14 insertions, 12 deletions

diff --git a/include/linux/mISDNhw.h b/include/linux/mISDNhw.h
index e794dfb87504..9384b92dfc65 100644
--- a/include/linux/mISDNhw.h
+++ b/include/linux/mISDNhw.h
@@ -57,20 +57,21 @@
 #define FLG_L2DATA              14      /* channel use L2 DATA primitivs */
 #define FLG_ORIGIN              15      /* channel is on origin site */
 /* channel specific stuff */
+#define FLG_FILLEMPTY           16      /* fill fifo on first frame (empty) */
 /* arcofi specific */
-#define FLG_ARCOFI_TIMER        16
-#define FLG_ARCOFI_ERROR        17
+#define FLG_ARCOFI_TIMER        17
+#define FLG_ARCOFI_ERROR        18
 /* isar specific */
-#define FLG_INITIALIZED         16
-#define FLG_DLEETX              17
-#define FLG_LASTDLE             18
-#define FLG_FIRST               19
-#define FLG_LASTDATA            20
-#define FLG_NMD_DATA            21
-#define FLG_FTI_RUN             22
-#define FLG_LL_OK               23
-#define FLG_LL_CONN             24
-#define FLG_DTMFSEND            25
+#define FLG_INITIALIZED         17
+#define FLG_DLEETX              18
+#define FLG_LASTDLE             19
+#define FLG_FIRST               20
+#define FLG_LASTDATA            21
+#define FLG_NMD_DATA            22
+#define FLG_FTI_RUN             23
+#define FLG_LL_OK               24
+#define FLG_LL_CONN             25
+#define FLG_DTMFSEND            26
 
 /* workq events */
 #define FLG_RECVQUEUE           30
diff --git a/include/linux/mISDNif.h b/include/linux/mISDNif.h
index 8f2d60da04e7..74c903cd7a0a 100644
--- a/include/linux/mISDNif.h
+++ b/include/linux/mISDNif.h
@@ -312,6 +312,7 @@ clear_channelmap(u_int nr, u_char *map)
 #define MISDN_CTRL_SETPEER              0x0040
 #define MISDN_CTRL_UNSETPEER            0x0080
 #define MISDN_CTRL_RX_OFF               0x0100
+#define MISDN_CTRL_FILL_EMPTY           0x0200
 #define MISDN_CTRL_HW_FEATURES_OP       0x2000
 #define MISDN_CTRL_HW_FEATURES          0x2001
 #define MISDN_CTRL_HFC_OP               0x4000