[media] cx23885: Configure the MPEG encoder early to avoid jerky video

Found an odd bug while implementing support for the HVR1850 that
lead to jerky video during the first capture, if the encoder was
not initialized early. I've modied the driver to configure the
encoder early, and this avoids the issue - a reasonable workaround.

Regression tested against the HVR1800 and soon to be added HVR1850

[mchehab@redhat.com: Fix this compilation issue:  drivers/media/video/cx23885/cx23885-417.c:1351:2: error: too few arguments to function ‘cx23885_initialize_codec’]
Signed-off-by: Steven Toth <stoth@kernellabs.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

diff --git a/drivers/media/video/cx23885/cx23885-417.c b/drivers/media/video/cx23885/cx23885-417.c
index f65e38cfb1d9704e5f58e8f6c1f9f03834213ccf..b5afa330dd28a520c838f1e2b73d4e1361617984 100644 (file)
--- a/drivers/media/video/cx23885/cx23885-417.c
+++ b/drivers/media/video/cx23885/cx23885-417.c
@@ -1044,7 +1044,7 @@ static void cx23885_codec_settings(struct cx23885_dev *dev)
        cx23885_api_cmd(dev, CX2341X_ENC_MISC, 2, 0, 4, 1);
 }
 
-static int cx23885_initialize_codec(struct cx23885_dev *dev)
+static int cx23885_initialize_codec(struct cx23885_dev *dev, int startencoder)
 {
        int version;
        int retval;
@@ -1126,9 +1126,11 @@ static int cx23885_initialize_codec(struct cx23885_dev *dev)
        mc417_memory_write(dev, 2120, 0x00000080);
 
        /* start capturing to the host interface */
-       cx23885_api_cmd(dev, CX2341X_ENC_START_CAPTURE, 2, 0,
-               CX23885_MPEG_CAPTURE, CX23885_RAW_BITS_NONE);
-       msleep(10);
+       if (startencoder) {
+               cx23885_api_cmd(dev, CX2341X_ENC_START_CAPTURE, 2, 0,
+                       CX23885_MPEG_CAPTURE, CX23885_RAW_BITS_NONE);
+               msleep(10);
+       }
 
        return 0;
 }
@@ -1346,7 +1348,7 @@ static int vidioc_s_frequency(struct file *file, void *priv,
 
        call_all(dev, tuner, s_frequency, f);
 
-       cx23885_initialize_codec(dev);
+       cx23885_initialize_codec(dev, 0);
 
        return 0;
 }
@@ -1650,7 +1652,7 @@ static ssize_t mpeg_read(struct file *file, char __user *data,
        /* Start mpeg encoder on first read. */
        if (atomic_cmpxchg(&fh->v4l_reading, 0, 1) == 0) {
                if (atomic_inc_return(&dev->v4l_reader_count) == 1) {
-                       if (cx23885_initialize_codec(dev) < 0)
+                       if (cx23885_initialize_codec(dev, 1) < 0)
                                return -EINVAL;
                }
        }
@@ -1805,5 +1807,11 @@ int cx23885_417_register(struct cx23885_dev *dev)
        printk(KERN_INFO "%s: registered device %s [mpeg]\n",
               dev->name, video_device_node_name(dev->v4l_device));
 
+       /* ST: Configure the encoder paramaters, but don't begin
+        * encoding, this resolves an issue where the first time the
+        * encoder is started video can be choppy.
+        */
+       cx23885_initialize_codec(dev, 0);
+
        return 0;
 }