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>

1 files changed, 11 insertions, 10 deletions

diff --git a/drivers/media/video/cx18/cx18-streams.c b/drivers/media/video/cx18/cx18-streams.c
index 6b0b7f751f20..d2690ccdf327 100644
--- a/drivers/media/video/cx18/cx18-streams.c
+++ b/drivers/media/video/cx18/cx18-streams.c
@@ -111,7 +111,6 @@ static void cx18_stream_init(struct cx18 *cx, int type)
 {
         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 @@ static void cx18_stream_init(struct cx18 *cx, int type)
         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 @@ static int cx18_prep_dev(struct cx18 *cx, int type)
         /* 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 @@ static int cx18_reg_dev(struct cx18 *cx, int type)
 
         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 @@ static int cx18_reg_dev(struct cx18 *cx, int type)
                 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);