From 9afd808cf3c45810492f2e05b7c422c99edc88cc Mon Sep 17 00:00:00 2001 From: =?UTF-8?q?Ville=20Syrj=C3=A4l=C3=A4?= Date: Thu, 8 Oct 2015 11:43:33 +0300 Subject: [PATCH] drm/edid: Round to closest when computing the CEA/HDMI alternate clock MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Rounding to the closest kHz seems like the better option that round down or up when computing the alternate clock for CEA/HDMI modes. It'll give us a slightly more accurate clock in some cases. Not sure why I went for the down+up approach originally. Perhaps I was thinking we can go back and forth betwen the two frequencies without introducing errors, but round to closest still maintains that property. Cc: Adam Jackson Cc: Clint Taylor Cc: Libin Yang Signed-off-by: Ville Syrjälä Reviewed-by: Adam Jackson Signed-off-by: Daniel Vetter --- drivers/gpu/drm/drm_edid.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/drivers/gpu/drm/drm_edid.c b/drivers/gpu/drm/drm_edid.c index 977915cf530a..d5d2c03fd136 100644 --- a/drivers/gpu/drm/drm_edid.c +++ b/drivers/gpu/drm/drm_edid.c @@ -2538,9 +2538,9 @@ cea_mode_alternate_clock(const struct drm_display_mode *cea_mode) * and the 60Hz variant otherwise. */ if (cea_mode->vdisplay == 240 || cea_mode->vdisplay == 480) - clock = clock * 1001 / 1000; + clock = DIV_ROUND_CLOSEST(clock * 1001, 1000); else - clock = DIV_ROUND_UP(clock * 1000, 1001); + clock = DIV_ROUND_CLOSEST(clock * 1000, 1001); return clock; }