[PATCH v3 3/8] ipu3-cio2: Validate mbus format in setting subdev format

[Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>]

Validate media bus code, width and height when setting the subdev format.

This effectively reworks how setting subdev format is implemented in the
driver.

Fixes: c2a6a07afe4a ("media: intel-ipu3: cio2: add new MIPI-CSI2 driver")
Signed-off-by: Sakari Ailus <sakari.ailus@xxxxxxxxxxxxxxx>
Reviewed-by: Andy Shevchenko <andy.shevchenko@xxxxxxxxx>
Reviewed-by: Laurent Pinchart <laurent.pinchart@xxxxxxxxxxxxxxxx>
Cc: stable@xxxxxxxxxxxxxxx # v4.16 and up
---
 drivers/media/pci/intel/ipu3/ipu3-cio2.c | 29 ++++++++++++++++--------
 1 file changed, 20 insertions(+), 9 deletions(-)

diff --git a/drivers/media/pci/intel/ipu3/ipu3-cio2.c b/drivers/media/pci/intel/ipu3/ipu3-cio2.c
index b3a08196e08c..72095f8a4d46 100644
--- a/drivers/media/pci/intel/ipu3/ipu3-cio2.c
+++ b/drivers/media/pci/intel/ipu3/ipu3-cio2.c
@@ -1257,6 +1257,9 @@ static int cio2_subdev_set_fmt(struct v4l2_subdev *sd,
 			       struct v4l2_subdev_format *fmt)
 {
 	struct cio2_queue *q = container_of(sd, struct cio2_queue, subdev);
+	struct v4l2_mbus_framefmt *mbus;
+	u32 mbus_code = fmt->format.code;
+	unsigned int i;
 
 	/*
 	 * Only allow setting sink pad format;
@@ -1265,18 +1268,26 @@ static int cio2_subdev_set_fmt(struct v4l2_subdev *sd,
 	if (fmt->pad == CIO2_PAD_SOURCE)
 		return cio2_subdev_get_fmt(sd, cfg, fmt);
 
-	mutex_lock(&q->subdev_lock);
+	if (fmt->which == V4L2_SUBDEV_FORMAT_TRY)
+		mbus = v4l2_subdev_get_try_format(sd, cfg, fmt->pad);
+	else
+		mbus = &q->subdev_fmt;
 
-	if (fmt->which == V4L2_SUBDEV_FORMAT_TRY) {
-		*v4l2_subdev_get_try_format(sd, cfg, fmt->pad) = fmt->format;
-	} else {
-		/* It's the sink, allow changing frame size */
-		q->subdev_fmt.width = fmt->format.width;
-		q->subdev_fmt.height = fmt->format.height;
-		q->subdev_fmt.code = fmt->format.code;
-		fmt->format = q->subdev_fmt;
+	fmt->format.code = formats[0].mbus_code;
+
+	for (i = 0; i < ARRAY_SIZE(formats); i++) {
+		if (formats[i].mbus_code == fmt->format.code) {
+			fmt->format.code = mbus_code;
+			break;
+		}
 	}
 
+	fmt->format.width = min_t(u32, fmt->format.width, CIO2_IMAGE_MAX_WIDTH);
+	fmt->format.height = min_t(u32, fmt->format.height,
+				   CIO2_IMAGE_MAX_LENGTH);
+
+	mutex_lock(&q->subdev_lock);
+	*mbus = fmt->format;
 	mutex_unlock(&q->subdev_lock);
 
 	return 0;
-- 
2.27.0