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authorDevin Heitmueller <dheitmueller@kernellabs.com>2009-05-27 23:25:36 -0300
committerMauro Carvalho Chehab <mchehab@redhat.com>2009-06-16 19:07:20 -0300
commitee3436b82886c0cb295354fb7ebbeadf3ff22105 (patch)
treeb615e19f61791ac98ce95621d4b746fa4c7fc750 /drivers
parent64a00b43e63c916f1bf4f6b7f519db0e198ba9d4 (diff)
V4L/DVB (11924): au0828: Don't let device work unless connected to a high speed USB port
The au0828 basically just doesn't work at 12 Mbps. The isoc pipe needs nearly 200 Mbps for analog support, so users would see garbage video, and on the DVB/ATSC side scanning is likely to work but if the user tried to tune it would certainly appear to have failed. It's better to fail explicity up front and tell the user to plug into a USB 2.0 port, than to let the driver load and the user have weird problems with tuning and garbage video. Signed-off-by: Devin Heitmueller <dheitmueller@kernellabs.com> Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
Diffstat (limited to 'drivers')
-rw-r--r--drivers/media/video/au0828/au0828-core.c12
1 files changed, 12 insertions, 0 deletions
diff --git a/drivers/media/video/au0828/au0828-core.c b/drivers/media/video/au0828/au0828-core.c
index a1e4c0d769a..2b3f64d7a7f 100644
--- a/drivers/media/video/au0828/au0828-core.c
+++ b/drivers/media/video/au0828/au0828-core.c
@@ -181,6 +181,18 @@ static int au0828_usb_probe(struct usb_interface *interface,
le16_to_cpu(usbdev->descriptor.idProduct),
ifnum);
+ /*
+ * Make sure we have 480 Mbps of bandwidth, otherwise things like
+ * video stream wouldn't likely work, since 12 Mbps is generally
+ * not enough even for most Digital TV streams.
+ */
+ if (usbdev->speed != USB_SPEED_HIGH) {
+ printk(KERN_ERR "au0828: Device initialization failed.\n");
+ printk(KERN_ERR "au0828: Device must be connected to a "
+ "high-speed USB 2.0 port.\n");
+ return -ENODEV;
+ }
+
dev = kzalloc(sizeof(*dev), GFP_KERNEL);
if (dev == NULL) {
printk(KERN_ERR "%s() Unable to allocate memory\n", __func__);