[PATCH 4/9] media: vimc: Ensure that pixel_rate fits in 32 bits

[Ricardo Ribalda]

pixel_rate is set to VIMC_PIXEL_RATE_FIXED, which the code expects to
fit in 32 bits. Make that constraint into a WARN_ON, so if we ever break
that constraint a kernel warning will be triggered.

It also fixes the following cocci warning:
./test-drivers/vimc/vimc-sensor.c:107:1-7: WARNING: do_div() does a 64-by-32 division, please consider using div64_u64 instead.

Signed-off-by: Ricardo Ribalda <ribalda@xxxxxxxxxxxx>
---
 drivers/media/test-drivers/vimc/vimc-sensor.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/media/test-drivers/vimc/vimc-sensor.c b/drivers/media/test-drivers/vimc/vimc-sensor.c
index d125a79fec8c..83dcc9d61ee0 100644
--- a/drivers/media/test-drivers/vimc/vimc-sensor.c
+++ b/drivers/media/test-drivers/vimc/vimc-sensor.c
@@ -103,8 +103,12 @@ static void vimc_sensor_update_frame_timing(struct v4l2_subdev *sd,
 	u64 total_pixels = (u64)hts * vts;
 	u64 frame_interval_ns;
 
+	/* Sanity check, pixel rate is fixed and fits in 32 bits. */
+	if (WARN_ON(pixel_rate >= 0x100000000))
+		return;
+
 	frame_interval_ns = total_pixels * NSEC_PER_SEC;
-	do_div(frame_interval_ns, pixel_rate);
+	do_div(frame_interval_ns, (u32)pixel_rate);
 	vsensor->hw.fps_jiffies = nsecs_to_jiffies(frame_interval_ns);
 	if (vsensor->hw.fps_jiffies == 0)
 		vsensor->hw.fps_jiffies = 1;

-- 
2.55.0.rc0.799.gd6f94ed593-goog