MLK-17401: drm: imx: dcss: fix scaling issue

Under certain circumstances (corner cases) the scaling fractions were
not set properly. This patch fixes this.

Signed-off-by: Laurentiu Palcu <laurentiu.palcu@nxp.com>

diff --git a/drivers/gpu/imx/dcss/dcss-scaler.c b/drivers/gpu/imx/dcss/dcss-scaler.c
index cdf5ea4..efe67bc 100644 (file)
--- a/drivers/gpu/imx/dcss/dcss-scaler.c
+++ b/drivers/gpu/imx/dcss/dcss-scaler.c
@@ -339,10 +339,10 @@ static bool dcss_scaler_fractions_set(struct dcss_soc *dcss, int ch_num,
 {
        u32 l_vinc, l_hinc, c_vinc, c_hinc;
 
-       l_vinc = (src_yres << 13) / dst_yres;
-       c_vinc = (src_yres << 13) / dst_yres;
-       l_hinc = (src_xres << 13) / dst_xres;
-       c_hinc = (src_xres << 13) / dst_xres;
+       l_vinc = ((src_yres << 13) + (dst_yres >> 1)) / dst_yres;
+       c_vinc = ((src_yres << 13) + (dst_yres >> 1)) / dst_yres;
+       l_hinc = ((src_xres << 13) + (dst_xres >> 1)) / dst_xres;
+       c_hinc = ((src_xres << 13) + (dst_xres >> 1)) / dst_xres;
 
        if (pix_format == DRM_FORMAT_UYVY || pix_format == DRM_FORMAT_VYUY ||
            pix_format == DRM_FORMAT_YUYV || pix_format == DRM_FORMAT_YVYU) {
@@ -389,8 +389,8 @@ bool dcss_scaler_can_scale(struct dcss_soc *dcss, int ch_num,
        const struct dcss_scaler_ratios *ratios_map = dcss_scaler_ratios;
 
        /* Convert to fixed point. Easier to work with. */
-       vscale_fp = (src_yres << 13) / dst_yres;
-       hscale_fp = (src_xres << 13) / dst_xres;
+       vscale_fp = ((src_yres << 13) + (dst_yres >> 1)) / dst_yres;
+       hscale_fp = ((src_xres << 13) + (dst_xres >> 1)) / dst_xres;
 
        if (scaler->ch_using_wrscl == -1 || scaler->ch_using_wrscl == ch_num)
                ratios_map = dcss_scaler_wrscl_ratios;