[media] gspca_main: Allow switching from read to mmap / userptr mode

Some applications (xawtv, qv4l2) mix read and mmap calls. Allow switching
from read mode back to mmap mode (by doing a reqbufs).

Signed-off-by: Hans de Goede <hdegoede@redhat.com>
Acked-by: Jean-Francois Moine <moinejf@free.fr>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

diff --git a/drivers/media/video/gspca/gspca.c b/drivers/media/video/gspca/gspca.c
index 244fb76..4ab906b 100644 (file)
--- a/drivers/media/video/gspca/gspca.c
+++ b/drivers/media/video/gspca/gspca.c
@@ -1497,6 +1497,7 @@ static int vidioc_reqbufs(struct file *file, void *priv,
                return -ERESTARTSYS;
 
        if (gspca_dev->memory != GSPCA_MEMORY_NO
+           && gspca_dev->memory != GSPCA_MEMORY_READ
            && gspca_dev->memory != rb->memory) {
                ret = -EBUSY;
                goto out;
@@ -1525,6 +1526,9 @@ static int vidioc_reqbufs(struct file *file, void *priv,
                gspca_stream_off(gspca_dev);
                mutex_unlock(&gspca_dev->usb_lock);
        }
+       /* Don't restart the stream when switching from read to mmap mode */
+       if (gspca_dev->memory == GSPCA_MEMORY_READ)
+               streaming = 0;
 
        /* free the previous allocated buffers, if any */
        if (gspca_dev->nframes != 0)