- minor vbi fix.

- add some latency debug code to the bttv irq handler
  (enable with debug_latency=1).

1 files changed, 28 insertions, 12 deletions

diff --git a/linux/drivers/media/video/bttv-driver.c b/linux/drivers/media/video/bttv-driver.c
index 39b1c3672..3712f827b 100644
--- a/linux/drivers/media/video/bttv-driver.c
+++ b/linux/drivers/media/video/bttv-driver.c
@@ -59,6 +59,7 @@ static unsigned int gbufsize = 0x208000;
 static int video_nr = -1;
 static int radio_nr = -1;
 static int vbi_nr = -1;
+static int debug_latency = 0;
 
 static unsigned int fdsr = 0;
 
@@ -98,6 +99,7 @@ MODULE_PARM_DESC(gbufsize,"size of the capture buffers, default is 0x208000");
 MODULE_PARM(video_nr,"i");
 MODULE_PARM(radio_nr,"i");
 MODULE_PARM(vbi_nr,"i");
+MODULE_PARM(debug_latency,"i");
 
 MODULE_PARM(fdsr,"i");
 
@@ -2177,13 +2179,13 @@ static int bttv_do_ioctl(struct inode *inode, struct file *file,
 				VID_TYPE_OVERLAY|
 				VID_TYPE_CLIPPING|
 				VID_TYPE_SCALES;
-			cap->channels  = bttv_tvcards[btv->c.type].video_inputs;
-			cap->audios    = bttv_tvcards[btv->c.type].audio_inputs;
 			cap->maxwidth  = bttv_tvnorms[btv->tvnorm].swidth;
 			cap->maxheight = bttv_tvnorms[btv->tvnorm].sheight;
 			cap->minwidth  = 48;
 			cap->minheight = 32;
 		}
+		cap->channels  = bttv_tvcards[btv->c.type].video_inputs;
+		cap->audios    = bttv_tvcards[btv->c.type].audio_inputs;
                 return 0;
 	}
 
@@ -3212,6 +3214,28 @@ static void bttv_print_riscaddr(struct bttv *btv)
 	       btv->screen ? (unsigned long long)btv->screen->bottom.dma : 0);
 }
 
+static void bttv_irq_debug_low_latency(struct bttv *btv, u32 rc)
+{
+	printk("bttv%d: irq: skipped frame [main=%lx,o_vbi=%lx,o_field=%lx,rc=%lx]\n",
+	       btv->c.nr,
+	       (unsigned long)btv->main.dma,
+	       (unsigned long)btv->main.cpu[RISC_SLOT_O_VBI+1],
+	       (unsigned long)btv->main.cpu[RISC_SLOT_O_FIELD+1],
+	       (unsigned long)rc);
+
+	if (0 == (btread(BT848_DSTATUS) & BT848_DSTATUS_HLOC)) {
+		printk("bttv%d: Oh, there (temporarely?) is no input signal. "
+		       "Ok, then this is harmless, don't worry ;)",
+		       btv->c.nr);
+		return;
+	}
+	printk("bttv%d: Uhm. Looks like we have unusual high IRQ latencies.\n",
+	       btv->c.nr);
+	printk("bttv%d: Lets try to catch the culpit red-handed ...\n",
+	       btv->c.nr);
+	dump_stack();
+}
+
 static int
 bttv_irq_next_set(struct bttv *btv, struct bttv_buffer_set *set)
 {
@@ -3401,16 +3425,8 @@ bttv_irq_switch_fields(struct bttv *btv)
 	rc = btread(BT848_RISC_COUNT);
 	if (rc < btv->main.dma || rc > btv->main.dma + 0x100) {
 		btv->framedrop++;
-		if (irq_debug) {
-			// TODO: dump_stack(); experiments
-			printk("bttv%d: skipped frame. no signal? high irq latency? "
-			       "[main=%lx,o_vbi=%lx,o_field=%lx,rc=%lx]\n",
-			       btv->c.nr,
-			       (unsigned long)btv->main.dma,
-			       (unsigned long)btv->main.cpu[RISC_SLOT_O_VBI+1],
-			       (unsigned long)btv->main.cpu[RISC_SLOT_O_FIELD+1],
-			       (unsigned long)rc);
-		}
+		if (debug_latency)
+			bttv_irq_debug_low_latency(btv, rc);
 		spin_unlock(&btv->s_lock);
 		return;
 	}