From 179f1aa407b466c06a94f9e54abc948d1e1146e7 Mon Sep 17 00:00:00 2001 From: Sebastian Hesselbarth Date: Wed, 14 Aug 2013 21:43:32 +0200 Subject: [PATCH] drm/i2c: tda998x: prepare for broken sync workaround Some LCD controller cannot provide valid VESA style sync, i.e. coincident HS/VS edges. First, this patch adds hskew passed from the adjusted_mode to reference pixel calculation to allow those controllers to add an offset relative to the expected reference pixel. Signed-off-by: Darren Etheridge Signed-off-by: Sebastian Hesselbarth Tested-by: Russell King Signed-off-by: Dave Airlie --- drivers/gpu/drm/i2c/tda998x_drv.c | 8 ++++++++ 1 file changed, 8 insertions(+) diff --git a/drivers/gpu/drm/i2c/tda998x_drv.c b/drivers/gpu/drm/i2c/tda998x_drv.c index 92fcb3d..c2bd711 100644 --- a/drivers/gpu/drm/i2c/tda998x_drv.c +++ b/drivers/gpu/drm/i2c/tda998x_drv.c @@ -782,6 +782,14 @@ tda998x_encoder_mode_set(struct drm_encoder *encoder, de_pix_s = mode->htotal - mode->hdisplay; ref_pix = 3 + hs_pix_s; + /* + * Attached LCD controllers may generate broken sync. Allow + * those to adjust the position of the rising VS edge by adding + * HSKEW to ref_pix. + */ + if (adjusted_mode->flags & DRM_MODE_FLAG_HSKEW) + ref_pix += adjusted_mode->hskew; + if ((mode->flags & DRM_MODE_FLAG_INTERLACE) == 0) { ref_line = 1 + mode->vsync_start - mode->vdisplay; vwin1_line_s = mode->vtotal - mode->vdisplay - 1; -- 2.7.4