From: Darren Etheridge <detheridge@xxxxxx> 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 <detheridge@xxxxxx> Signed-off-by: Sebastian Hesselbarth <sebastian.hesselbarth@xxxxxxxxx> --- Changelog: for v1: - reword comment Cc: David Airlie <airlied@xxxxxxxx> Cc: Darren Etheridge <detheridge@xxxxxx> Cc: Rob Clark <robdclark@xxxxxxxxx> Cc: Russell King <rmk+kernel@xxxxxxxxxxxxxxxx> Cc: Daniel Vetter <daniel.vetter@xxxxxxxx> Cc: dri-devel@xxxxxxxxxxxxxxxxxxxxx Cc: linux-kernel@xxxxxxxxxxxxxxx --- drivers/gpu/drm/i2c/tda998x_drv.c | 9 +++++++++ 1 file changed, 9 insertions(+) diff --git a/drivers/gpu/drm/i2c/tda998x_drv.c b/drivers/gpu/drm/i2c/tda998x_drv.c index 7bf227a..7dc5650 100644 --- a/drivers/gpu/drm/i2c/tda998x_drv.c +++ b/drivers/gpu/drm/i2c/tda998x_drv.c @@ -784,6 +784,15 @@ tda998x_encoder_mode_set(struct drm_encoder *encoder, n_line = mode->vtotal; ref_pix = 3 + mode->hsync_start - mode->hdisplay; + + /* + * 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; + de_pix_s = mode->htotal - mode->hdisplay; de_pix_e = de_pix_s + mode->hdisplay; hs_pix_s = mode->hsync_start - mode->hdisplay; -- 1.7.10.4 _______________________________________________ dri-devel mailing list dri-devel@xxxxxxxxxxxxxxxxxxxxx http://lists.freedesktop.org/mailman/listinfo/dri-devel
