From mboxrd@z Thu Jan 1 00:00:00 1970 From: Sebastian Hesselbarth Subject: [PATCH 7/8] drm/i2c: tda998x: prepare for broken sync workaround Date: Tue, 6 Aug 2013 00:20:17 +0200 Message-ID: <1375741218-10225-8-git-send-email-sebastian.hesselbarth@gmail.com> References: <1375741218-10225-1-git-send-email-sebastian.hesselbarth@gmail.com> Return-path: In-Reply-To: <1375741218-10225-1-git-send-email-sebastian.hesselbarth@gmail.com> Sender: linux-kernel-owner@vger.kernel.org To: Sebastian Hesselbarth Cc: Darren Etheridge , David Airlie , Rob Clark , Russell King , Daniel Vetter , dri-devel@lists.freedesktop.org, linux-kernel@vger.kernel.org List-Id: dri-devel@lists.freedesktop.org From: Darren Etheridge 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 --- Changelog: for v1: - reword comment Cc: David Airlie Cc: Darren Etheridge Cc: Rob Clark Cc: Russell King Cc: Daniel Vetter Cc: dri-devel@lists.freedesktop.org Cc: linux-kernel@vger.kernel.org --- 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