V4L/DVB (9802): cx18: Add module parameters for finer control over buffer allocations

cx18: Add module parameters for finer control over buffer allocations.
User now has the option of setting smaller buffers to get lower
latency transfers from the encoder.  User can also now set the number
of buffers used for a stream explicitly.

Signed-off-by: Andy Walls <awalls@radix.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
diff --git a/drivers/media/video/cx18/cx18-streams.c b/drivers/media/video/cx18/cx18-streams.c
index 6b0b7f75..d2690cc 100644
--- a/drivers/media/video/cx18/cx18-streams.c
+++ b/drivers/media/video/cx18/cx18-streams.c
@@ -111,7 +111,6 @@
 {
 	struct cx18_stream *s = &cx->streams[type];
 	struct video_device *dev = s->v4l2dev;
-	u32 max_size = cx->options.megabytes[type] * 1024 * 1024;
 
 	/* we need to keep v4l2dev, so restore it afterwards */
 	memset(s, 0, sizeof(*s));
@@ -124,9 +123,9 @@
 	s->handle = CX18_INVALID_TASK_HANDLE;
 
 	s->dma = cx18_stream_info[type].dma;
+	s->buffers = cx->stream_buffers[type];
 	s->buf_size = cx->stream_buf_size[type];
-	if (s->buf_size)
-		s->buffers = max_size / s->buf_size;
+
 	mutex_init(&s->qlock);
 	init_waitqueue_head(&s->waitq);
 	s->id = -1;
@@ -162,7 +161,7 @@
 	/* User explicitly selected 0 buffers for these streams, so don't
 	   create them. */
 	if (cx18_stream_info[type].dma != PCI_DMA_NONE &&
-	    cx->options.megabytes[type] == 0) {
+	    cx->stream_buffers[type] == 0) {
 		CX18_INFO("Disabled %s device\n", cx18_stream_info[type].name);
 		return 0;
 	}
@@ -262,8 +261,9 @@
 
 	switch (vfl_type) {
 	case VFL_TYPE_GRABBER:
-		CX18_INFO("Registered device video%d for %s (%d MB)\n",
-			num, s->name, cx->options.megabytes[type]);
+		CX18_INFO("Registered device video%d for %s (%d x %d kB)\n",
+			  num, s->name, cx->stream_buffers[type],
+			  cx->stream_buf_size[type]/1024);
 		break;
 
 	case VFL_TYPE_RADIO:
@@ -272,10 +272,11 @@
 		break;
 
 	case VFL_TYPE_VBI:
-		if (cx->options.megabytes[type])
-			CX18_INFO("Registered device vbi%d for %s (%d MB)\n",
-				num,
-				s->name, cx->options.megabytes[type]);
+		if (cx->stream_buffers[type])
+			CX18_INFO("Registered device vbi%d for %s "
+				  "(%d x %d bytes)\n",
+				  num, s->name, cx->stream_buffers[type],
+				  cx->stream_buf_size[type]);
 		else
 			CX18_INFO("Registered device vbi%d for %s\n",
 				num, s->name);