diff --git a/drivers/gpu/drm/i2c/tda998x_drv.c b/drivers/gpu/drm/i2c/tda998x_drv.c index 92fcb3deae22..c2bd711e86e9 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;