[PATCH 3/3] gpu: ipu-v3: image-convert: Fix image downsize coefficients

From: Steve Longerbeam
Date: Tue Jun 11 2019 - 21:21:48 EST


The output of the IC downsizer unit in both dimensions must be <= 1024
before being passed to the IC resizer unit. This was causing corrupted
images when:

input_dim > 1024, and
input_dim / 2 < output_dim < input_dim

Some broken examples were 1920x1080 -> 1024x768 and 1920x1080 ->
1280x1080.

Fixes: 70b9b6b3bcb21 ("gpu: ipu-v3: image-convert: calculate per-tile
resize coefficients")

Signed-off-by: Steve Longerbeam <slongerbeam@xxxxxxxxx>
---
drivers/gpu/ipu-v3/ipu-image-convert.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/gpu/ipu-v3/ipu-image-convert.c b/drivers/gpu/ipu-v3/ipu-image-convert.c
index 4dfdbd1adf0d..e744f3527ce1 100644
--- a/drivers/gpu/ipu-v3/ipu-image-convert.c
+++ b/drivers/gpu/ipu-v3/ipu-image-convert.c
@@ -400,12 +400,14 @@ static int calc_image_resize_coefficients(struct ipu_image_convert_ctx *ctx,
if (WARN_ON(resized_width == 0 || resized_height == 0))
return -EINVAL;

- while (downsized_width >= resized_width * 2) {
+ while (downsized_width > 1024 ||
+ downsized_width >= resized_width * 2) {
downsized_width >>= 1;
downsize_coeff_h++;
}

- while (downsized_height >= resized_height * 2) {
+ while (downsized_height > 1024 ||
+ downsized_height >= resized_height * 2) {
downsized_height >>= 1;
downsize_coeff_v++;
}
--
2.17.1