[media] em28xx: ignore isoc DVB USB endpoints with wMaxPacketSize = 0 bytes for all alt settings

Some devices without DVB support (such as the "Terratec Grabby" and
"Easycap DC-60") provide isochronous DVB USB endpoints with wMaxPacketSize set
to 0 bytes for all alt settings.
Ignore these endpoints and avoid registering a DVB device node and loading the
DVB driver extension.

Signed-off-by: Frank Schäfer <fschaefer.oss@googlemail.com>
Tested-by: Timo Teräs <timo.teras@iki.fi>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>
This commit is contained in:
Frank Schaefer 2013-03-27 16:07:41 -03:00 коммит произвёл Mauro Carvalho Chehab
Родитель b418697115
Коммит 72cc9ba39a
1 изменённых файлов: 8 добавлений и 1 удалений

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@ -3357,14 +3357,15 @@ static int em28xx_usb_probe(struct usb_interface *interface,
dev->analog_ep_bulk =
e->bEndpointAddress;
} else {
has_dvb = true;
if (usb_endpoint_xfer_isoc(e)) {
dev->dvb_ep_isoc = e->bEndpointAddress;
if (size > dev->dvb_max_pkt_size_isoc) {
has_dvb = true; /* see NOTE (~) */
dev->dvb_max_pkt_size_isoc = size;
dev->dvb_alt_isoc = i;
}
} else {
has_dvb = true;
dev->dvb_ep_bulk = e->bEndpointAddress;
}
}
@ -3391,6 +3392,12 @@ static int em28xx_usb_probe(struct usb_interface *interface,
* so far. But there might be devices for which this
* logic is not sufficient...
*/
/*
* NOTE (~): some manufacturers (e.g. Terratec) disable
* endpoints by setting wMaxPacketSize to 0 bytes for
* all alt settings. So far, we've seen this for
* DVB isoc endpoints only.
*/
}
}