From eec77da2744b1265653ab99af91c3b26c49501e9 Mon Sep 17 00:00:00 2001 From: Tomi Valkeinen Date: Mon, 27 Jan 2014 11:29:53 +0200 Subject: [PATCH] OMAPDSS: DISPC: decimation rounding fix 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 --- drivers/video/omap2/dss/dispc.c | 16 ++++++++-------- 1 file changed, 8 insertions(+), 8 deletions(-) diff --git a/drivers/video/omap2/dss/dispc.c b/drivers/video/omap2/dss/dispc.c index bbeb8dd7f108..77d6221618f4 100644 --- a/drivers/video/omap2/dss/dispc.c +++ b/drivers/video/omap2/dss/dispc.c @@ -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 || -- 2.34.1