[media] airspy: fill FMT buffer size

Fill FMT buffer size field in order to inform app which will be
used streaming buffer size. Currently driver doesn't allow buffer
size value proposed by application.

Cc: Hans Verkuil <[e-mail]>
Signed-off-by: Antti Palosaari <[e-mail]>
Signed-off-by: Mauro Carvalho Chehab <[e-mail]>

drivers/media/usb/airspy/airspy.c

···
 struct airspy_format {
 	char	*name;
 	u32	pixelformat;
+	u32	buffersize;
 };
 
 /* format descriptions for capture and preview */
 static struct airspy_format formats[] = {
 	{
 		.name		= "Real U12LE",
-		.pixelformat	=  V4L2_SDR_FMT_RU12LE,
+		.pixelformat	= V4L2_SDR_FMT_RU12LE,
+		.buffersize	= BULK_BUFFER_SIZE,
 	},
 };
 
···
 	unsigned int f_adc;
 	unsigned int f_rf;
 	u32 pixelformat;
+	u32 buffersize;
 
 	/* Controls */
 	struct v4l2_ctrl_handler hdl;
···
 	if (vq->num_buffers + *nbuffers < 8)
 		*nbuffers = 8 - vq->num_buffers;
 	*nplanes = 1;
-	sizes[0] = PAGE_ALIGN(BULK_BUFFER_SIZE);
+	sizes[0] = PAGE_ALIGN(s->buffersize);
 
 	dev_dbg(&s->udev->dev, "%s: nbuffers=%d sizes[0]=%d\n",
 			__func__, *nbuffers, sizes[0]);
···
 	dev_dbg(&s->udev->dev, "%s: pixelformat fourcc %4.4s\n", __func__,
 			(char *)&s->pixelformat);
 
-	memset(f->fmt.sdr.reserved, 0, sizeof(f->fmt.sdr.reserved));
 	f->fmt.sdr.pixelformat = s->pixelformat;
+	f->fmt.sdr.buffersize = s->buffersize;
+	memset(f->fmt.sdr.reserved, 0, sizeof(f->fmt.sdr.reserved));
 
 	return 0;
 }
···
 	memset(f->fmt.sdr.reserved, 0, sizeof(f->fmt.sdr.reserved));
 	for (i = 0; i < NUM_FORMATS; i++) {
 		if (formats[i].pixelformat == f->fmt.sdr.pixelformat) {
-			s->pixelformat = f->fmt.sdr.pixelformat;
+			s->pixelformat = formats[i].pixelformat;
+			s->buffersize = formats[i].buffersize;
+			f->fmt.sdr.buffersize = formats[i].buffersize;
 			return 0;
 		}
 	}
 
-	f->fmt.sdr.pixelformat = formats[0].pixelformat;
 	s->pixelformat = formats[0].pixelformat;
+	s->buffersize = formats[0].buffersize;
+	f->fmt.sdr.pixelformat = formats[0].pixelformat;
+	f->fmt.sdr.buffersize = formats[0].buffersize;
 
 	return 0;
 }
···
 
 	memset(f->fmt.sdr.reserved, 0, sizeof(f->fmt.sdr.reserved));
 	for (i = 0; i < NUM_FORMATS; i++) {
-		if (formats[i].pixelformat == f->fmt.sdr.pixelformat)
+		if (formats[i].pixelformat == f->fmt.sdr.pixelformat) {
+			f->fmt.sdr.buffersize = formats[i].buffersize;
 			return 0;
+		}
 	}
 
 	f->fmt.sdr.pixelformat = formats[0].pixelformat;
+	f->fmt.sdr.buffersize = formats[0].buffersize;
 
 	return 0;
 }
···
 	s->udev = udev;
 	s->f_adc = bands[0].rangelow;
 	s->f_rf = bands_rf[0].rangelow;
-	s->pixelformat = V4L2_SDR_FMT_RU12LE;
+	s->pixelformat = formats[0].pixelformat;
+	s->buffersize = formats[0].buffersize;
 
 	/* Detect device */
 	ret = airspy_ctrl_msg(s, CMD_BOARD_ID_READ, 0, 0, &u8tmp, 1);