[Linux1394-cvslog] rev 717 - trunk

[SVN U. <ano...@li...>]

Author: anonymous
Date: 2002-12-20 03:20:59 -0500 (Fri, 20 Dec 2002)
New Revision: 717

Modified:
   trunk/ohci1394.c
Log:
improve iso transmit underflow detection by checking for discontinuity of cycle count

Modified: trunk/ohci1394.c
==============================================================================
--- trunk/ohci1394.c	(original)
+++ trunk/ohci1394.c	2002-12-22 09:50:42.000000000 -0500
@@ -1389,6 +1389,7 @@
 	struct ohci1394_iso_tasklet task;
 	int task_active;
 	int pkt_dma;
+	int last_cycle;
 
 	u32 ContextControlSet;
 	u32 ContextControlClear;
@@ -1426,7 +1427,8 @@
 	xmit->ohci = iso->host->hostdata;
 	xmit->task_active = 0;
 	xmit->pkt_dma = iso->first_packet;
-	
+	xmit->last_cycle = -1;
+
 	dma_prog_region_init(&xmit->prog);
 	
 	prog_size = sizeof(struct iso_xmit_cmd) * iso->buf_packets;
@@ -1509,24 +1511,34 @@
 		}
 
 		if(event != 0x11) {
+			atomic_inc(&iso->overflows);
 			PRINT(KERN_ERR, xmit->ohci->id, "IT DMA error - OHCI error code 0x%02x\n", event);
 		}
 		
 		/* at least one packet went out, so wake up the writer */
 		wake = 1;
-		
-		/* predict the timestamp pkt_dma will have next time around the buffer */
+
+		/* parse cycle */
 		{
 			struct hpsb_iso_packet_info* info = hpsb_iso_packet_info(iso, xmit->pkt_dma);
 			unsigned int cycle = cmd->output_last.status & 0x1FFF;
 
+			/* check for discontinuity */
+			if(xmit->last_cycle != -1 && cycle != (xmit->last_cycle+1) % 8000) {
+				atomic_inc(&iso->overflows);
+			}
+			xmit->last_cycle = cycle;
+
+			/* predict the timestamp pkt_dma will have
+			   next time around the buffer */
+			
 			cycle += iso->buf_packets;
-			while(cycle > 8000)
+			while(cycle >= 8000)
 				cycle -= 8000;
-			
+
 			info->cycle = cycle;
 		}
-		
+
 		/* reset the DMA descriptor for next time */
 		cmd->output_last.status = 0;
 		
@@ -1646,6 +1658,8 @@
 {
 	struct ohci_iso_xmit *xmit = iso->hostdata;
 
+	xmit->last_cycle = -1;
+
 	/* clear out the control register */
 	reg_write(xmit->ohci, xmit->ContextControlClear, 0xFFFFFFFF);
 	wmb();