2 files changed, 69 insertions, 17 deletions

diff --git a/linux/drivers/media/dvb/ttpci-budget/budget-core.c b/linux/drivers/media/dvb/ttpci-budget/budget-core.c
index 90b4d4227..d7ce45356 100644
--- a/linux/drivers/media/dvb/ttpci-budget/budget-core.c
+++ b/linux/drivers/media/dvb/ttpci-budget/budget-core.c
@@ -105,32 +105,80 @@ TTBStart(struct budget_s *budget)
         return ++budget->feeding;
 }
 
+/* TS_PACKETS is minumum number of accumulated 188-byte packets 
+** (TS_SIZE=188) that is considered 'complete' and can
+** be delivered to the sw_demux in one 'quantum'.
+** TS_QUANTUM is size in bytes of TS_PACKETS
+** TS_MAX_PACKETS is number of TS_PACKETS in one DMA window
+** TS_BUFLEN is 1024*188
+*/
 static
 void fidbirq (unsigned long data)
 {
 	struct budget_s *budget = (struct budget_s*) data;
 	u8 *mem=(u8 *)(budget->grabbing);
-	int num=512;
-	int field=0x80 & saa7146_read(budget->dev, PSR);
+	u8 oldtsf = budget->tsf;
+	u8 newtsf = 0x80 & saa7146_read(budget->dev, PSR);
+	u16 oldpkt = budget->ttbp;
+	u16 newpkt = saa7146_read(budget->dev, PCI_VDP3)/TS_QUANTUM; /* PCI_VDP3 = 0..TS_BUFLEN-1 */
+	u8 *olddma = mem + oldpkt*TS_QUANTUM; /* rounded to first complete packet */
 
 	DEB_EE(("budget: %p\n",budget));
+	
+	/* Zero-Packet-Loss fidbirq by EMARD */
 
-	if (field) {
-		if (field==budget->tsf)
-			num=1024;
-		else
-			mem+=TS_BUFLEN/2;
-	} else {
-		if (field==budget->tsf) {
-			if (budget->feeding && mem[TS_BUFLEN/2]==0x47)
-				dvb_dmx_swfilter_packets(&budget->demux, 
-				    mem+TS_BUFLEN/2, 512 );
+	budget->ttbp = newpkt;
+	budget->tsf = newtsf;
+	
+	/* exit immediately when the card is not set for feeding
+	** or when values are out of expected boundaries
+	*/
+	if(budget->feeding == 0 ||
+		oldpkt >= TS_MAX_PACKETS || newpkt >= TS_MAX_PACKETS)
+		return;
+
+	/* use heuristic methods for recovering from lost interrupt
+	*/
+	if(oldtsf == newtsf)
+	{
+		/* interrupt is probably lost, some data can't be
+		** retrieved because of DMA overwriting, but let's 
+		** try to save what is left of good data in the DMA
+		** window.
+		*/
+		if(newpkt != oldpkt)
+		{	/* DMA is probably in progress right now,
+			** overwriting data. Shift oldpkt 1 packets
+			** forward from newpkt as a gap for racing with 
+			** ongoing DMA transfer. Consider TS_MAX_PACKETS-1 packets
+			** are still valid in DMA window.
+			*/
+			oldpkt = (newpkt + 1) % TS_MAX_PACKETS;
+			olddma = mem + oldpkt*TS_QUANTUM;
+			/* from now on, proceed as usual */
 		}
 	}
 
-	budget->tsf=field;
-	if (budget->feeding && mem[0]==0x47)
-		dvb_dmx_swfilter_packets(&budget->demux, mem, num);
+	if(oldpkt < newpkt)
+	{	/* no wraparound - dump linear data
+		** from olddma to newdma
+		*/
+		if(*olddma == 0x47)
+			dvb_dmx_swfilter_packets(&budget->demux, olddma,
+				TS_PACKETS*(newpkt-oldpkt));
+	}
+	else
+	{ 	/* wraparound - dump in two chunks,
+		** from olddma to end of DMA window
+		** and from begin of DMA window to newdma
+		*/
+		if(*olddma == 0x47)
+			dvb_dmx_swfilter_packets(&budget->demux, olddma,
+				TS_PACKETS*(TS_MAX_PACKETS - oldpkt));
+		if(*mem == 0x47 && newpkt > 0)
+			dvb_dmx_swfilter_packets(&budget->demux, mem,
+				TS_PACKETS*newpkt);
+	}			
 }
 
 inline static void 
diff --git a/linux/drivers/media/dvb/ttpci-budget/budget.h b/linux/drivers/media/dvb/ttpci-budget/budget.h
index 7df52e804..0a0a5b16b 100644
--- a/linux/drivers/media/dvb/ttpci-budget/budget.h
+++ b/linux/drivers/media/dvb/ttpci-budget/budget.h
@@ -46,8 +46,8 @@ struct budget_s {
         int                     fe_synced; 
         struct semaphore        pid_mutex;
 
-        int tsf;
-        u32 ttbp;
+        u8 tsf;
+        u16 ttbp;
         int feeding;
 
         int registered;
@@ -68,6 +68,10 @@ static struct saa7146_pci_extension_data x_var = { \
 #define TS_HEIGHT (1024/4)
 #define TS_BUFLEN (TS_WIDTH*TS_HEIGHT)
 
+#define TS_PACKETS	1
+#define TS_QUANTUM	(TS_PACKETS*TS_SIZE)
+#define TS_MAX_PACKETS	(TS_BUFLEN/TS_QUANTUM)
+
 #define BUDGET_TT		   0
 #define BUDGET_TT_HW_DISEQC	   1
 #define BUDGET_KNC1		   2