V4L/DVB (11247): hdpvr: empty internal device buffer after stopping streaming

Makes the next capturing starting faster and more reliable.

Signed-off-by: Janne Grunau <j@jannau.net>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

1 files changed, 26 insertions, 0 deletions

diff --git a/drivers/media/video/hdpvr/hdpvr-video.c b/drivers/media/video/hdpvr/hdpvr-video.c
index f6e1bcefddb7..3e6ffee8dfed 100644
--- a/drivers/media/video/hdpvr/hdpvr-video.c
+++ b/drivers/media/video/hdpvr/hdpvr-video.c
@@ -298,11 +298,20 @@ static int hdpvr_start_streaming(struct hdpvr_device *dev)
 /* function expects dev->io_mutex to be hold by caller */
 static int hdpvr_stop_streaming(struct hdpvr_device *dev)
 {
+        uint actual_length, c = 0;
+        u8 *buf;
+
         if (dev->status == STATUS_IDLE)
                 return 0;
         else if (dev->status != STATUS_STREAMING)
                 return -EAGAIN;
 
+        buf = kmalloc(dev->bulk_in_size, GFP_KERNEL);
+        if (!buf)
+                v4l2_err(&dev->v4l2_dev, "failed to allocate temporary buffer "
+                         "for emptying the internal device buffer. "
+                         "Next capture start will be slow\n");
+
         dev->status = STATUS_SHUTTING_DOWN;
         hdpvr_config_call(dev, CTRL_STOP_STREAMING_VALUE, 0x00);
         mutex_unlock(&dev->io_mutex);
@@ -316,6 +325,23 @@ static int hdpvr_stop_streaming(struct hdpvr_device *dev)
         /* kill the still outstanding urbs */
         hdpvr_cancel_queue(dev);
 
+        /* emptying the device buffer beforeshutting it down */
+        while (buf && ++c < 500 &&
+               !usb_bulk_msg(dev->udev,
+                             usb_rcvbulkpipe(dev->udev,
+                                             dev->bulk_in_endpointAddr),
+                             buf, dev->bulk_in_size, &actual_length,
+                             BULK_URB_TIMEOUT)) {
+                /* wait */
+                msleep(5);
+                v4l2_dbg(MSG_BUFFER, hdpvr_debug, &dev->v4l2_dev,
+                         "%2d: got %d bytes\n", c, actual_length);
+        }
+        kfree(buf);
+        v4l2_dbg(MSG_BUFFER, hdpvr_debug, &dev->v4l2_dev,
+                 "used %d urbs to empty device buffers\n", c-1);
+        msleep(10);
+
         dev->status = STATUS_IDLE;
 
         return 0;