[media] media: ov7670: make try_fmt() consistent with 'min_height' and 'min_width'

'min_height' and 'min_width' are variables that allow to specify the minimum
resolution that the sensor will achieve. This patch make v4l2 fmt callbacks
consider this parameters in order to return valid data to user space.
Acked-by: Jonathan Corbet <corbet@lwn.net>
Signed-off-by: Javier Martin <javier.martin@vista-silicon.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/i2c/ov7670.c

@@ -786,10 +786,11 @@ static int ov7670_try_fmt_internal(struct v4l2_subdev *sd,
 		struct ov7670_format_struct **ret_fmt,
 		struct ov7670_win_size **ret_wsize)
 {
-	int index;
+	int index, i;
 	struct ov7670_win_size *wsize;
 	struct ov7670_info *info = to_state(sd);
 	unsigned int n_win_sizes = info->devtype->n_win_sizes;
+	unsigned int win_sizes_limit = n_win_sizes;
 
 	for (index = 0; index < N_OV7670_FMTS; index++)
 		if (ov7670_formats[index].mbus_code == fmt->code)
@@ -805,15 +806,30 @@ static int ov7670_try_fmt_internal(struct v4l2_subdev *sd,
 	 * Fields: the OV devices claim to be progressive.
 	 */
 	fmt->field = V4L2_FIELD_NONE;
+
+	/*
+	 * Don't consider values that don't match min_height and min_width
+	 * constraints.
+	 */
+	if (info->min_width || info->min_height)
+		for (i = 0; i < n_win_sizes; i++) {
+			wsize = info->devtype->win_sizes + i;
+
+			if (wsize->width < info->min_width ||
+				wsize->height < info->min_height) {
+				win_sizes_limit = i;
+				break;
+			}
+		}
 	/*
 	 * Round requested image size down to the nearest
 	 * we support, but not below the smallest.
 	 */
 	for (wsize = info->devtype->win_sizes;
-	     wsize < info->devtype->win_sizes + n_win_sizes; wsize++)
+	     wsize < info->devtype->win_sizes + win_sizes_limit; wsize++)
 		if (fmt->width >= wsize->width && fmt->height >= wsize->height)
 			break;
-	if (wsize >= info->devtype->win_sizes + n_win_sizes)
+	if (wsize >= info->devtype->win_sizes + win_sizes_limit)
 		wsize--;   /* Take the smallest one */
 	if (ret_wsize != NULL)
 		*ret_wsize = wsize;