[PATCH 4.17 227/336] media: em28xx: fix a regression with HVR-950

[Greg Kroah-Hartman]

4.17-stable review patch.  If anyone has any objections, please let me know.

------------------

From: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx>

[ Upstream commit 509f89652f83e834b3ef7a083e2eeac812b055f0 ]

Commit be7fd3c3a8c5 ("media: em28xx: Hauppauge DualHD second tuner
functionality") removed the logic with sets the alternate for the DVB
device. Without setting the right alternate, the device won't be
able to submit URBs, and userspace fails with -EMSGSIZE:

	ERROR     DMX_SET_PES_FILTER failed (PID = 0x2000): 90 Message too long

Tested with Hauppauge HVR-950 model A1C0.

Fixes: be7fd3c3a8c5 ("media: em28xx: Hauppauge DualHD second tuner functionality")

Cc: Brad Love <brad@xxxxxxxxxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab@xxxxxxxxxxxxxxxx>
Signed-off-by: Mauro Carvalho Chehab <mchehab+samsung@xxxxxxxxxx>
Signed-off-by: Sasha Levin <alexander.levin@xxxxxxxxxxxxx>
Signed-off-by: Greg Kroah-Hartman <gregkh@xxxxxxxxxxxxxxxxxxx>
---
 drivers/media/usb/em28xx/em28xx-dvb.c |    2 ++
 1 file changed, 2 insertions(+)

--- a/drivers/media/usb/em28xx/em28xx-dvb.c
+++ b/drivers/media/usb/em28xx/em28xx-dvb.c
@@ -199,6 +199,7 @@ static int em28xx_start_streaming(struct
 	int rc;
 	struct em28xx_i2c_bus *i2c_bus = dvb->adapter.priv;
 	struct em28xx *dev = i2c_bus->dev;
+	struct usb_device *udev = interface_to_usbdev(dev->intf);
 	int dvb_max_packet_size, packet_multiplier, dvb_alt;
 
 	if (dev->dvb_xfer_bulk) {
@@ -217,6 +218,7 @@ static int em28xx_start_streaming(struct
 		dvb_alt = dev->dvb_alt_isoc;
 	}
 
+	usb_set_interface(udev, dev->ifnum, dvb_alt);
 	rc = em28xx_set_mode(dev, EM28XX_DIGITAL_MODE);
 	if (rc < 0)
 		return rc;