From dc0cf4cfed89d3a784a8d1c5897fae8f6a137fa5 Mon Sep 17 00:00:00 2001 From: Prashant Laddha Date: Fri, 5 Jun 2015 05:13:31 -0300 Subject: [PATCH] [media] v4l2-dv-timing: avoid rounding twice in gtf hblank calc Currently, in gtf hblank calculations, the rounding is used twice, one at intermediate division and one at final state where hblank is rounded to nearest multiple of twice cell granularity. This error got introduced in 'commit d7ed5a3ddaec ("[media] v4l2-dv-timings: fix rounding in hblank and hsync calculation"), where it missed combining the rounding step. Correcting the same in this patch. Signed-off-by: Prashant Laddha Signed-off-by: Hans Verkuil Signed-off-by: Mauro Carvalho Chehab --- drivers/media/v4l2-core/v4l2-dv-timings.c | 10 ++++++---- 1 file changed, 6 insertions(+), 4 deletions(-) diff --git a/drivers/media/v4l2-core/v4l2-dv-timings.c b/drivers/media/v4l2-core/v4l2-dv-timings.c index 5792192..8986610 100644 --- a/drivers/media/v4l2-core/v4l2-dv-timings.c +++ b/drivers/media/v4l2-core/v4l2-dv-timings.c @@ -561,20 +561,22 @@ bool v4l2_detect_gtf(unsigned frame_height, num = ((image_width * GTF_D_C_PRIME * (u64)hfreq) - ((u64)image_width * GTF_D_M_PRIME * 1000)); - den = hfreq * (100 - GTF_D_C_PRIME) + GTF_D_M_PRIME * 1000; + den = (hfreq * (100 - GTF_D_C_PRIME) + GTF_D_M_PRIME * 1000) * + (2 * GTF_CELL_GRAN); h_blank = div_u64((num + (den >> 1)), den); + h_blank *= (2 * GTF_CELL_GRAN); } else { u64 num; u32 den; num = ((image_width * GTF_S_C_PRIME * (u64)hfreq) - ((u64)image_width * GTF_S_M_PRIME * 1000)); - den = hfreq * (100 - GTF_S_C_PRIME) + GTF_S_M_PRIME * 1000; + den = (hfreq * (100 - GTF_S_C_PRIME) + GTF_S_M_PRIME * 1000) * + (2 * GTF_CELL_GRAN); h_blank = div_u64((num + (den >> 1)), den); + h_blank *= (2 * GTF_CELL_GRAN); } - h_blank = ((h_blank + GTF_CELL_GRAN) / (2 * GTF_CELL_GRAN)) * - (2 * GTF_CELL_GRAN); frame_width = image_width + h_blank; pix_clk = (image_width + h_blank) * hfreq; -- 2.7.4