mISDN: Implement MISDN_CTRL_FILL_EMPTY for more drivers

MISDN_CTRL_FILL_EMPTY is a meachanism to send a fixed value (normally silence)
as long no data from upper layers is available. It can be used when recording
voice messages or with unidirectional protocols.

Signed-off-by: Karsten Keil <kkeil@linux-pingi.de>
Signed-off-by: David S. Miller <davem@davemloft.net>

2 files changed, 12 insertions, 1 deletions

diff --git a/drivers/isdn/mISDN/dsp_core.c b/drivers/isdn/mISDN/dsp_core.c
index 2ac2d7a25a9f..28c99c623bcd 100644
--- a/drivers/isdn/mISDN/dsp_core.c
+++ b/drivers/isdn/mISDN/dsp_core.c
@@ -268,6 +268,7 @@ dsp_fill_empty(struct dsp *dsp)
         }
         cq.op = MISDN_CTRL_FILL_EMPTY;
         cq.p1 = 1;
+        cq.p2 = dsp_silence;
         if (dsp->ch.peer->ctrl(dsp->ch.peer, CONTROL_CHANNEL, &cq)) {
                 printk(KERN_DEBUG "%s: CONTROL_CHANNEL failed\n",
                        __func__);
diff --git a/drivers/isdn/mISDN/hwchannel.c b/drivers/isdn/mISDN/hwchannel.c
index d42ad0e98de3..e541b65f68ba 100644
--- a/drivers/isdn/mISDN/hwchannel.c
+++ b/drivers/isdn/mISDN/hwchannel.c
@@ -140,6 +140,8 @@ mISDN_clear_bchannel(struct bchannel *ch)
         test_and_clear_bit(FLG_TX_BUSY, &ch->Flags);
         test_and_clear_bit(FLG_TX_NEXT, &ch->Flags);
         test_and_clear_bit(FLG_ACTIVE, &ch->Flags);
+        test_and_clear_bit(FLG_FILLEMPTY, &ch->Flags);
+        test_and_clear_bit(FLG_TX_EMPTY, &ch->Flags);
         ch->minlen = ch->init_minlen;
         ch->next_minlen = ch->init_minlen;
         ch->maxlen = ch->init_maxlen;
@@ -165,7 +167,15 @@ mISDN_ctrl_bchannel(struct bchannel *bch, struct mISDN_ctrl_req *cq)
 
         switch (cq->op) {
         case MISDN_CTRL_GETOP:
-                cq->op = MISDN_CTRL_RX_BUFFER;
+                cq->op = MISDN_CTRL_RX_BUFFER | MISDN_CTRL_FILL_EMPTY;
+                break;
+        case MISDN_CTRL_FILL_EMPTY:
+                if (cq->p1) {
+                        memset(bch->fill, cq->p2 & 0xff, MISDN_BCH_FILL_SIZE);
+                        test_and_set_bit(FLG_FILLEMPTY, &bch->Flags);
+                } else {
+                        test_and_clear_bit(FLG_FILLEMPTY, &bch->Flags);
+                }
                 break;
         case MISDN_CTRL_RX_BUFFER:
                 if (cq->p2 > MISDN_CTRL_RX_SIZE_IGNORE)