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From:   Steve Longerbeam <slongerbeam@gmail.com>
To:     Philipp Zabel <p.zabel@pengutronix.de>
Cc:     Steve Longerbeam <slongerbeam@gmail.com>,
        dri-devel@lists.freedesktop.org (open list:DRM DRIVERS FOR FREESCALE
        IMX), linux-kernel@vger.kernel.org (open list)
Subject: [PATCH 3/3] gpu: ipu-v3: image-convert: Fix image downsize coefficients
Date:   Tue, 11 Jun 2019 18:16:57 -0700
Message-Id: <20190612011657.12119-3-slongerbeam@gmail.com>
In-Reply-To: <20190612011657.12119-1-slongerbeam@gmail.com>
References: <20190612011657.12119-1-slongerbeam@gmail.com>
Sender: linux-kernel-owner@vger.kernel.org
Precedence: bulk

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@gmail.com>
---
 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