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OMAPDSS: DISPC: decimation rounding fix

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The driver uses DIV_ROUND_UP when calculating decimated width & height.
For example, when decimating with 3, the width is calculated as:

  width = DIV_ROUND_UP(width, decim_x);

This yields bad results for some values. For example, 800/3=266.666...,
which is rounded to 267. When the input width is set to 267, and pixel
increment is set to 3, this causes the dispc to read a line of 801
pixels, i.e. it reads a wrong pixel at the end of the line.

Even more pressing, the above rounding causes a BUG() in pixinc(), as
the value of 801 is used to calculate row increment, leading to a bad
value being passed to pixinc().

This patch fixes the decimation by removing the DIV_ROUND_UP()s when
calculating width and height for decimation.

Signed-off-by: Tomi Valkeinen <tomi.valkeinen@ti.com>
This commit is contained in:
Tomi Valkeinen 2014-01-27 11:29:53 +02:00
parent b28a960c42
commit eec77da274
1 changed files with 8 additions and 8 deletions
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16
drivers/video/omap2/dss/dispc.c
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@ -2160,8 +2160,8 @@ static int dispc_ovl_calc_scaling_24xx(unsigned long pclk, unsigned long lclk,
*five_taps = false;
do {
in_height = DIV_ROUND_UP(height, *decim_y);
in_width = DIV_ROUND_UP(width, *decim_x);
in_height = height / *decim_y;
in_width = width / *decim_x;
*core_clk = dispc.feat->calc_core_clk(pclk, in_width,
in_height, out_width, out_height, mem_to_mem);
error = (in_width > maxsinglelinewidth || !*core_clk ||
@ -2199,8 +2199,8 @@ static int dispc_ovl_calc_scaling_34xx(unsigned long pclk, unsigned long lclk,
dss_feat_get_param_max(FEAT_PARAM_LINEWIDTH);
do {
in_height = DIV_ROUND_UP(height, *decim_y);
in_width = DIV_ROUND_UP(width, *decim_x);
in_height = height / *decim_y;
in_width = width / *decim_x;
*five_taps = in_height > out_height;
if (in_width > maxsinglelinewidth)
@ -2268,7 +2268,7 @@ static int dispc_ovl_calc_scaling_44xx(unsigned long pclk, unsigned long lclk,
{
u16 in_width, in_width_max;
int decim_x_min = *decim_x;
u16 in_height = DIV_ROUND_UP(height, *decim_y);
u16 in_height = height / *decim_y;
const int maxsinglelinewidth =
dss_feat_get_param_max(FEAT_PARAM_LINEWIDTH);
const int maxdownscale = dss_feat_get_param_max(FEAT_PARAM_DOWNSCALE);
@ -2287,7 +2287,7 @@ static int dispc_ovl_calc_scaling_44xx(unsigned long pclk, unsigned long lclk,
return -EINVAL;
do {
in_width = DIV_ROUND_UP(width, *decim_x);
in_width = width / *decim_x;
} while (*decim_x <= *x_predecim &&
in_width > maxsinglelinewidth && ++*decim_x);
@ -2466,8 +2466,8 @@ static int dispc_ovl_setup_common(enum omap_plane plane,
if (r)
return r;
in_width = DIV_ROUND_UP(in_width, x_predecim);
in_height = DIV_ROUND_UP(in_height, y_predecim);
in_width = in_width / x_predecim;
in_height = in_height / y_predecim;
if (color_mode == OMAP_DSS_COLOR_YUV2 ||
color_mode == OMAP_DSS_COLOR_UYVY ||